diff --git a/pkg/secrets/strategy.go b/pkg/secrets/strategy.go
index 498328a48..c475a9d3e 100644
--- a/pkg/secrets/strategy.go
+++ b/pkg/secrets/strategy.go
@@ -13,20 +13,6 @@ import (
 // This is the output of resolving a parameter or credential set file.
 type Set map[string]string
 
-// Merge merges a second Set into the base.
-//
-// Duplicate names are not allow and will result in an
-// error, this is the case even if the values are identical.
-func (s Set) Merge(s2 Set) error {
-	for k, v := range s2 {
-		if _, ok := s[k]; ok {
-			return fmt.Errorf("ambiguous value resolution: %q is already present in base sets, cannot merge", k)
-		}
-		s[k] = v
-	}
-	return nil
-}
-
 // IsValid determines if the provided key (designating a name of a parameter
 // or credential) is included in the provided set
 func (s Set) IsValid(key string) bool {
@@ -130,18 +116,84 @@ func (s Source) MarshalYAML() (interface{}, error) {
 	return s.MarshalRaw(), nil
 }
 
-type StrategyList []SourceMap
+// SourceMapList is a list of mappings that can be access via index or the item name.
+type SourceMapList []SourceMap
 
-func (l StrategyList) Less(i, j int) bool {
+func (l SourceMapList) Less(i, j int) bool {
 	return l[i].Name < l[j].Name
 }
 
-func (l StrategyList) Swap(i, j int) {
+func (l SourceMapList) Swap(i, j int) {
 	tmp := l[i]
 	l[i] = l[j]
 	l[j] = tmp
 }
 
-func (l StrategyList) Len() int {
+func (l SourceMapList) Len() int {
 	return len(l)
 }
+
+// HasName determines if the specified name is defined in the set.
+func (l SourceMapList) HasName(name string) bool {
+	_, ok := l.GetByName(name)
+	return ok
+}
+
+// GetByName returns the resolution strategy for the specified name and a bool indicating if it was found.
+func (l SourceMapList) GetByName(name string) (SourceMap, bool) {
+	for _, item := range l {
+		if item.Name == name {
+			return item, true
+		}
+	}
+
+	return SourceMap{}, false
+}
+
+// GetResolvedValue returns the resolved value of the specified name and a bool indicating if it was found.
+// You must resolve the value before calling, it does not do resolution for you.
+func (l SourceMapList) GetResolvedValue(name string) (interface{}, bool) {
+	item, ok := l.GetByName(name)
+	if ok {
+		return item.ResolvedValue, true
+	}
+
+	return nil, false
+}
+
+// ToResolvedValues converts the items to a map of key/value pairs, with the resolved values represented as CNAB-compatible strings
+func (l SourceMapList) ToResolvedValues() map[string]string {
+	values := make(map[string]string, len(l))
+	for _, item := range l {
+		values[item.Name] = item.ResolvedValue
+	}
+	return values
+}
+
+// Merge applies the specified values on top of a base set of values. When a
+// name exists in both sets, use the value from the overrides
+func (l SourceMapList) Merge(overrides SourceMapList) SourceMapList {
+	result := l
+
+	// Make a lookup from the name to its index in result so that we can quickly find a
+	// named item while merging
+	lookup := make(map[string]int, len(result))
+	for i, item := range result {
+		lookup[item.Name] = i
+	}
+
+	for _, item := range overrides {
+		// If the name is in the base, overwrite its value with the override provided
+		if i, ok := lookup[item.Name]; ok {
+			result[i].Source = item.Source
+
+			// Just in case the value was resolved, include in the merge results
+			result[i].ResolvedValue = item.ResolvedValue
+		} else {
+			// Append the override to the list of results if it's not in the base set of values
+			result = append(result, item)
+		}
+	}
+
+	return result
+}
diff --git a/pkg/secrets/strategy_test.go b/pkg/secrets/strategy_test.go
index 8e5478fe9..da00d7f66 100644
--- a/pkg/secrets/strategy_test.go
+++ b/pkg/secrets/strategy_test.go
@@ -1,30 +1,105 @@
 package secrets
 
 import (
+	"sort"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
-func TestSet_Merge(t *testing.T) {
-	set := Set{
-		"first":  "first",
-		"second": "second",
-		"third":  "third",
+func TestSourceMapList_GetResolvedValue(t *testing.T) {
+	l := SourceMapList{
+		SourceMap{Name: "bar", ResolvedValue: "2"},
+		SourceMap{Name: "foo", ResolvedValue: "1"},
+	}
+
+	fooVal, ok := l.GetResolvedValue("foo")
+	require.True(t, ok, "foo could not be found")
+	assert.Equal(t, "1", fooVal, "foo had the incorrect resolved value")
+
+	_, ok = l.GetResolvedValue("missing")
+	require.False(t, ok, "GetResolvedValue should have returned that missing key was not found")
+}
+
+func TestSourceMapList_GetResolvedValues(t *testing.T) {
+	l := SourceMapList{
+		SourceMap{Name: "bar", ResolvedValue: "2"},
+		SourceMap{Name: "foo", ResolvedValue: "1"},
+	}
+
+	want := map[string]string{
+		"bar": "2",
+		"foo": "1",
+	}
+	got := l.ToResolvedValues()
+	assert.Equal(t, want, got)
+}
+
+func TestSourceMapList_HasKey(t *testing.T) {
+	l := SourceMapList{
+		SourceMap{Name: "bar", ResolvedValue: "2"},
+		SourceMap{Name: "foo", ResolvedValue: "1"},
+	}
+
+	require.True(t, l.HasName("foo"), "HasName returned the wrong value for a key present in the list")
+	require.False(t, l.HasName("missing"), "HasName returned the wrong value for a missing key")
+}
+
+func TestSourceMapList_Sort(t *testing.T) {
+	l := SourceMapList{
+		SourceMap{Name: "c"},
+		SourceMap{Name: "a"},
+		SourceMap{Name: "b"},
+	}
+
+	sort.Sort(l)
+
+	wantResult := SourceMapList{
+		SourceMap{Name: "a"},
+		SourceMap{Name: "b"},
+		SourceMap{Name: "c"},
+	}
+
+	require.Len(t, l, 3, "Len is not implemented correctly")
+	require.Equal(t, wantResult, l, "Sort is not implemented correctly")
+}
+
+func TestSourceMapList_GetStrategy(t *testing.T) {
+	wantToken := SourceMap{Name: "token", Source: Source{Strategy: "env", Hint: "GITHUB_TOKEN"}}
+	l := SourceMapList{
+		SourceMap{Name: "logLevel", Source: Source{Strategy: "value", Hint: "11"}},
+		wantToken,
+	}
+
+	gotToken, ok := l.GetByName("token")
+	require.True(t, ok, "GetByName did not find 'token'")
+	assert.Equal(t, wantToken, gotToken, "GetByName returned the wrong 'token' strategy")
+}
+
+func TestSourceMapList_Merge(t *testing.T) {
+	set := SourceMapList{
+		SourceMap{Name: "first", ResolvedValue: "base first"},
+		SourceMap{Name: "second", ResolvedValue: "base second"},
+		SourceMap{Name: "third", ResolvedValue: "base third"},
 	}
 
 	is := assert.New(t)
 
-	err := set.Merge(Set{})
-	is.NoError(err)
-	is.Len(set, 3)
-	is.NotContains(set, "fourth")
+	result := set.Merge(SourceMapList{})
+	is.Len(result, 3)
+	_, ok := result.GetResolvedValue("base fourth")
+	is.False(ok, "forth should not be present in the base set")
 
-	err = set.Merge(Set{"fourth": "fourth"})
-	is.NoError(err)
-	is.Len(set, 4)
-	is.Contains(set, "fourth")
+	result = set.Merge(SourceMapList{SourceMap{Name: "fourth", ResolvedValue: "new fourth"}})
+	is.Len(result, 4)
+	val, ok := result.GetResolvedValue("fourth")
+	is.True(ok, "fourth should be present when merged as an override")
+	is.Equal("new fourth", val, "incorrect merged value")
 
-	err = set.Merge(Set{"second": "bis"})
-	is.EqualError(err, `ambiguous value resolution: "second" is already present in base sets, cannot merge`)
+	result = set.Merge(SourceMapList{SourceMap{Name: "second", ResolvedValue: "override second"}})
+	is.Len(result, 3)
+	val, ok = result.GetResolvedValue("second")
+	is.True(ok, "second should be overwritten when an override value is merged")
+	is.Equal("override second", val, "incorrect merged value")
 }
diff --git a/pkg/storage/credentialset.go b/pkg/storage/credentialset.go
index 651fd5252..07bc0577a 100644
--- a/pkg/storage/credentialset.go
+++ b/pkg/storage/credentialset.go
@@ -50,7 +50,7 @@ type CredentialSetSpec struct {
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty" toml:"labels,omitempty"`
 
 	// Credentials is a list of credential resolution strategies.
-	Credentials secrets.StrategyList `json:"credentials" yaml:"credentials" toml:"credentials"`
+	Credentials secrets.SourceMapList `json:"credentials" yaml:"credentials" toml:"credentials"`
 }
 
 // CredentialSetStatus contains additional status metadata that has been set by Porter.
diff --git a/pkg/storage/parameterset.go b/pkg/storage/parameterset.go
index 66f104c8c..c31ffeecf 100644
--- a/pkg/storage/parameterset.go
+++ b/pkg/storage/parameterset.go
@@ -44,7 +44,7 @@ type ParameterSetSpec struct {
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty" toml:"labels,omitempty"`
 
 	// Parameters is a list of parameter specs.
-	Parameters secrets.StrategyList `json:"parameters" yaml:"parameters" toml:"parameters"`
+	Parameters secrets.SourceMapList `json:"parameters" yaml:"parameters" toml:"parameters"`
 }
 
 // ParameterSetStatus contains additional status metadata that has been set by Porter.