Well I'm also glad to hear that you failed at fostering. I know I would too so this is why I've never fostered. I'm glad to hear that they're getting along fairly well. My females are the ones that aren't very accepting to newbies and they will even fight with each other or their older male siblings too.

Have you tried using Feliway spray or plugins at all? Sometimes it'll work well and sometimes not. I've used it in the past but after a while my cats seemed to become immune to it. I look forward to hearing more about your krew of 5 and hopefully seeing many more pictures too. Good luck.