Indeed. I think it may be a difference in emphasis by the manufacturer. "Here, three types of hoplite" versus our attitude at WF, which is "This set allows to make a wide variety of things."We could, of course, have offered the Numidians with extra sprues (and new box art) as Greek light infantry, Spanish, Thracians etc. But what we'd be doing is going to a lot of expense to sell mostly the same thing, and probably not adding to our market much. We'd rather say, "See my Ligurians! Numidian bodies, Celtic arms and shields, German heads, paper cloaks!" and have you make some than try to sell Ligurians, and find only 200 people bought the set.
In fairness, the basic hoplite kit is so versatile that all is needed is extra heads and arms to make pretty much everything from the hellenic period. Save of course the later-era 'Thorakiti' models with their mail and scale armour. And some proper warhorses to model decent-size shock cavalry.
Hmm. Come September and the plastic hoplites niche is expanding 600%. Going from 1 kit from Immortal to 3 Immortal kits and 3 more Victrix kits. That's definitely getting close to market saturation as far as even as ubiquitous a solider as hoplites get.