I guess I have a mental block when it comes to accepting throw-away weapons like pila as a primary weapon. Of course, in a literal sense it is the first weapon to be used (i.e. "primary"), but once it's thrown it's not going to be used in that battle again and the legionnaires carried only a couple of them. I'm trying to recall my undergrad Roman history class, but I believe pila were used as a preparatory weapon before closing in with the sword and shield. The Romans are usually considered to be one of the world's few (only?) sword armies. While the point is probably overstated, and the full breadth of their tactics often overlooked, in my mind the sword was the Romans' primary weapon (if by primary, we mean "main" weapon).

The sword-and-buckler men from the Thirty Years War (not sure if "buckler" is the correct term - it's a good sized shield), are shown in the new Osprey book. Yes they often carried pistols, but again, early single-shot pistols in melee would have a similar preparatory function. (Although I seem to recall there being pistol-armed cavalry that used a caracole tactic, they performed a different battlefield function).