It's capable. They used on the A-10A, which was mounted on a different station (2 and 10, instead of 3 and 9 now with the Charlie), so some people say this implies in a few issues with the main landing gear wheel being 'burnt' by the rocket motor, but IMHO that's nonsense.
The issue with the triple Mavericks boils down to drag and weight. LAU-88 which is the rack used to mount the Mavericks adds a considerable amount of mass to the aircraft, and drag as well, the drag index is very high, especially when you mount all three Mavericks on it. Although it was used in the past, this kind of loadout isn't used anymore due to the performance penalties, a lighter, less draggy airframe is sometimes more efficient. I'm not even sure if LAU-88 + 3xMavs is authorized anymore, but to a certain degree, yes it's realistic, and if you need to use it in the sim, USE it. Don't be afraid of using it because some individuals in this community are saying it's not realistic. This is a game and real life is something else.