Depending on what 'some others' are, it should 'work.' A large male mandarin will get at least 3", so he should be big enough not to peak the other fish's interest. They are quick enough when they have to be, and I don't see why you have to worry about other fish 'out-competing' it as they usually only eat pods. I would definitely not recommend adding another pod-eater though. However, I myself, have run this equation through my head. I was considering a leopard wrasse for my agressive tank (a large leopard will definitely hold it's own). However I realized how vital the pods are in a tank. They help control nusiance algae (to an extent), and consume excessive food and fish waste. Especially important in set-ups that don't allow traditional CUC's.
I guess my bottom line, is they should be okay, however, this might cause some changes, like having to do larger, more frequent water changes. And prepping the tank for a mandarin. A bunch of small rubble rock piles in the tank and a strongly recommended refugium addition, if not already planned.