You can put a french angel in with a flame or any other dwarf angel without any problems. I would just make sure that you get a big enough french angel so that there is a big size difference. Also, you can have more than one flame angel in a tank you just have to make sure that you are certain you have a pair, which they can be sexed based on appearence it is just not easy to do. I would ask copps as he know lots about dwarf angels.