You can. But, you'll have to have a huge food supply for them.
If the question is "Will they fight?" The answer is, more than likely they will not. Mandarins are not really fighters
If it's a decent size tank and you have a good supply of pods in the tank and a refugium, you should be okay.
To me, however, it's more hassle than it's worth.
We have a green spotted and my husband desperately wants a red or blue and I've been fighting him tooth and nail about it.