Am I correct in thinking that the Legionaire pog is a generic?

(In that it represents the teenage fanboys who haven't been given full membership into the LoSH.)

A friend of mine got a shed load of them in his case and (as I'm sure that is what they are) I consoled him by telling him this...

There is no official definition of "generic".

If your venue uses some kind of only one named character rule, you'll have to ask your judge. Personally, I'd say, "yes, they are generic pieces," but that is just my opinion.