i have three of my bettas side-by-side. Delta, HMPK, PK. Ichi, Stephano, Lulu. Lu's never had issues with being able to see a male. Stephano loves showing off. it's boosted his confidence alot, imo. went from super shy boy who stayed clamped, to active boy who's always showing off. he flares at Ichi, hides in his plants when tired of that. flirts with Lulu, goes to sleep in plants. keeps Ichi active, as well. Lulu..... is getting old. she puts up with Stephano's eagerness, but generally ignores him. sometimes she flirts back, though. it's kinda cute...
as for keeeping males and females together.... my setup is the closest i'll get. i DID want to get a 5 and divide it between my rescues, but decided against it. because of the risk. i don't want to have to IM their savior and say 'well, Fritter passed away.... got eggbound and burst." that'd be horrid. D8