Totally missed this post.
I wonder if you had a male Red tail? I had both sexes I believe, and the female (I assume) was larger (as is standard) and ran the tank. I even had her in a cichlid tank for a while and she held her own, and could easily out maneuver them all. She lived to be like 9...
So I walk in to put some hay down, change their water etc, Aniron starts playing and instead of blasting me out, the geese settled right down like someone just tucked them in!
Yeah my post left a lot to be desired there heh.
So I'm going to get the Red Tail alone, with some compatible community fish so I'll at least need a 30 gallon there.
For the Beta it's a giant so it would need even bigger. https://splashyfishstore.com/collections/giant-betta
The cichlids...