diff --git a/src/ytdl_sub/entries/script/function_scripts.py b/src/ytdl_sub/entries/script/function_scripts.py
index 8d0702c1..696bef35 100644
--- a/src/ytdl_sub/entries/script/function_scripts.py
+++ b/src/ytdl_sub/entries/script/function_scripts.py
@@ -50,19 +50,20 @@ CUSTOM_FUNCTION_SCRIPTS: Dict[str, str] = {
                         %regex_capture_groups
                     ),
                     %array_size($2),
-                    %eq
+                    %lte
                 ),
                 %and
             ),
-            %array_first(
+            %array_overlay(
                 %array_apply_fixed(
                     %array($1),
                     %string($0),
                     %regex_search
                 ),
-                %array_extend( ['dummy'], $2 )
+                %array_extend( ['using all defaults'], $2 ),
+                True
             ),
-            'Number of regex capture groups must be the same for every input regex'
+            'Number of regex capture groups must be less than or equal to the number of defaults'
         )
     }""",
 }
diff --git a/src/ytdl_sub/script/functions/array_functions.py b/src/ytdl_sub/script/functions/array_functions.py
index 1e6a6ca8..9dbbe4cf 100644
--- a/src/ytdl_sub/script/functions/array_functions.py
+++ b/src/ytdl_sub/script/functions/array_functions.py
@@ -50,6 +50,25 @@ class ArrayFunctions:
 
         return Array(output)
 
+    @staticmethod
+    def array_overlay(
+        array: Array, overlap: Array, only_missing: Optional[Boolean] = None
+    ) -> Array:
+        """
+        Overlaps ``overlap`` onto ``array``. Can optionally only overlay missing indices.
+        """
+        output: List[Resolvable] = []
+        output.extend(array.value)
+
+        overlap_only_missing = only_missing and only_missing.value
+
+        for idx, overlap_value in enumerate(overlap.value):
+            if overlap_only_missing and idx < len(array.value):
+                continue
+            output.insert(idx, overlap_value)
+
+        return Array(output)
+
     @staticmethod
     def array_at(array: Array, idx: Integer) -> AnyArgument:
         """