The questions are what size tank are they in now, how old/big are they, and what gender?
If they're smaller fish growing up together you may see a whole different dynamic once adult hormones kick in-- it's a mistake to think because juvenile cichlids get along peacefully they'll always get along. If it's male/female or two females it's possible they'll work out, but no guarantee. If it's two males you definitely don't want to be putting them in a smaller tank-- if that's the deal. Putting them into a larger tank might be ok or maybe ok for a while if they're still growing. Then again, it might give them just enough territory to fight over. The thing is they can vary by age, gender, size, circumstances in their tank, changes in tank-- and by individual fish. Makes these kind of situations hard to predict.