One exception is the squad my friends and i have taken to using in Operations, given that playing Attackers is a pain in the ass. We play three support, a medic, and a scout. The whole point of this is being an auxiliary, more than outright rushing the point. The supports will use the 'talking guns' approach for trying to suppress and kill enemies on the point, either through mortars or MGs. The scout is for spotting, precision fire on high value targets, medics and elites specifically, and for sentry duty (as in keeping an eye out for people rushing the supports, not for taking the Sentry kit). The medic of the squad stays between the supports, and friendlies that are pushing the line. His role is to support the push with medical aid while he keeps himself close enough to see what the scout might have missed, and to call whichever support doesn't have mortars available (the redeploy time is kind of a pain, but i think it's fair) to the line in the event he finds himself or the assaulting squads low on ammunition. This really only works about half of the times we actually use it, but when it does work it is hilarious how many people you can see scattering from the point we're sending Steel Rain at.

that's not an [i]exception[/i], that's an [b][i][u]example[/u][/i][/b] of a balanced squad lol that's the whole point of the game, squad up and balance it out and play the objective tactically good on you sir, hopefully I see you in random matchmaking on my team when you're solo lol

I meant in the case of having one of each class it's an exception, my apologies.