they could be. Theurophoroi seems to be a generic ancient term for mercenary medium foot.
"Thureophoroi are usually distinguished from both skirmishers and the phalanx and seem to have operated in a role intermediate between the two types. They often supported light troops and seemed to be capable of operating in a similar manner to peltasts. The thureophoroi were well suited to the tactical needs for smaller states, mainly border defense. They were mobile and could rapidly advance over varied terrain. According to Plutarch, they could fight as skirmishers and then fall back, assume spears and tighten the ranks, forming a phalanx.[1]"
http://en.wikipedia.org/wiki/Thureophoroi
That said their javelins are a bit short for Offensive spears. I had the same problem with Old Glory Theurophoroi and had to replace their short spears with piano wire.