This happens an awful lot with frontend components, which is the basic reason a lot of component systems end up failing. It's really common for things that are

This happens an awful lot with frontend components, which is the basic reason a lot of component systems end up failing. It's really common for things that are merely similar to look 'duck-type style' literally the same early on when they're basic. But the similarity is just an intersection. As things get more advanced the non overlapping bits come in, conditionals get added, compromises are made, and things end up a mess. Often all along there should have just been two copies of the markup / behaviour that just happened to be the same in the beginning. Then when things change you add, statically, exactly the extra things you need to either one.