I need a gerbil expert

[Autocratic]

So my roommate got a gerbil a few months ago for our apartment. It's been fine. Today he brought home another gerbil upon being told by a Petsmart expert that it would be fine. However, they tend to scrap when placed in the same cage. Buying a new cage is a hassle, so we were wondering if the gerbils will eventually stop doing battle and start getting along. If there is no other option we might witness a gerbilfight to the gerbildeath.