EU uses Comm, Rifle, MM (usually Assassination) and Assa for dps. Rec, Med, Demo as support. Engi is preference, but mostly field. That's EC with exped setup. We mostly skip the MM, Assa and Engi though and get say a 2nd comm or more rifles. For Alpha its usually 1-2 Orderbats, 1 FA med, 1 SRec, rest whatever they want.