Nice vids! looks like they're playing "king of the cube". I don't think they really hurt each other, as long as everyone gets food it should be ok.
Toothcarps? I think of that term as guppies & killifish (& similar), not a specific fish (like cichlid), maybe that's my age showing, lol.
Thanks for the link, they look nice. They sound kinda tricky (but I think that about any fish needing slightly brackish) & red listed, added pressure to get them to breed. Good luck!