Betta Fish: Should I swap my fish tanks?

Hi everyone! You’ve all been so helpful on this forum for fish advice and I’m happy to say I’ve gotten such a long way as a fish Mom thanks to you!

I think I need some advice regarding my two little sweeties. I currently have one high needs guy who developed dragon scales over his eye and is half blind, he’s also been battling some overall health issues since getting him from the store and I’ve been treating light swim bladder issues for the last little while. I think because he is limited vision, he gulps air while feeding and overall he has become a very chill shy guy now. He mostly rests in his hammock and on his lily pads and swords, and he will come towards my finger and eat, but then he finds another spot to rest. During the day he will swim around a little bit or go down to the bottom and watch the shrimp meetings. I originally have him in a 10 gallon heavily planted tank with all the equipment and wonder if because he’s mostly hanging out in one area if maybe this tank is too big for him and I should downsize.

I recently just got given a adorable young female from a sad sorority tank so I put her in my planted 5 gallon since I was told generally females are a bit more chill and might not need the extra space. But she is younger and quite a bit more active and curious than my older guy so I was wondering if it would be worth it to switch their tanks?

I also love my older guy so much and don’t want to stress him out since he has a limited vision and knows the layout of the tank and where all of his hiding spots are. Obviously, if I downsize him, I will put his beta log and favourite floating leaf in, but just wanted to know your thoughts!