Uhh, but you said interface inheritance, which isn't really composition... And favoring composition will definitely complicate the design.
Your logic doesn't make sense. Subtyping creates coupling. That makes sense, but you didn't follow through with your argument. I already said that it's generally bad, which means it's not always bad to do so, and you've (sort of) agreed with me in your last sentences.
Finally, using interfaces, sub-types, and/or composition will produce their own "clutter code". You FAVOR composition over inheritance, not FAVOR ONLY composition. Otherwise, we wouldn't be having this conversation. I suggest you read (or re-read) Design Patterns by the Gang of Four.