I have a betta with some ADFs, currently just two since I didn't properly plug a hole and one disappeared on me.

But my betta is a puppy personality wise and the most aggressive he gets is when its bloodworm day because he recognizes the tweezers and will immediately dart for them if I don't feed him first. (I usually cup him on frozen food days, as the frogs' tray is well covered and he leaves their pellets alone, but sometimes I get a little lazy and just distract my betta while feeding the frogs), but even that is towards the food and not the frogs. The frogs get a little nippy during bloodworm feeding days as well. I think they can smell it because the moment my tweezers touch the water they'll nip anything that get's in front of them. Even each other.
It's working out for me, but it was never meant to be a permanent arrangement (the betta was an impulse buy since he was so sickly and had been at PetCo for so long), and I have a back up tank just in case something goes wrong. Eventually, I plan on moving the betta out and giving the tank to the frogs, since it's theirs and he's just subletting, but for now they are all living together quite happily. Until then I've upped my water changes to every three days and keep a careful eye on things.
On the ACF vs ADF, I'm glad I did research before buying and learned the ways too tell. There was a female African Clawed Frog at the pet store the day I went to get my ADFs and the salesman kept trying to get me to buy her, claiming she was an ADF. I think he just wanted to get rid of her, because he was really pushy.