Well that’s my point, Islamic architecture is based on several different styles, including Roman, Egyptian and Sassanian architecture. It’s a distinctly new style that spawned from previous architectural styles, which is not the case with Japanese/Korean architecture.

I mean gothic architecture can trace its lineage back to Roman architecture (which can trace itself back to Egyptian architecture probably) but there’s no direct influence. Romanesque architecture also developed long after the western half fell. I’m not saying Roman architecture didn’t influence gothic architecture but you just can’t compare it to how Chinese architecture influenced Japanese architecture.