Yeah, they preferred javelins/atl-atls and bows didn’t come into full use until the classical period; but skirmishers aren’t an offensive option in aoe2 so it was rounded up to the more viable denominator. Save magyars, there aren’t civs defined by being trash unit civs
I’m pretty certain the Mayans had Jaguar caste or something egregiously similar since the Aztecs WERE Mayans (that split off from mayapan to found their own territory) and the Jaguar caste precludes them all entirely because it was originally Olmec stipulation, and was adopted by Zapotecs and later cultures.
Again, this goes back to the fine and necessary line between game balance and history 
That’s the same as saying that Mayans shouldn’t be given arbalest because they didn’t actually have crossbows. Everything is rounded up for balance - do we not give Incans gold units because they didn’t have gold? Ancient pre-empire incans weren’t warlike and communed amongst themselves as an agricultural society, but there was still travel between the Andean states. The foundations set from the Chavin and Caral cultures made a precedent of a theocratic class.
Of course, Frankish axes weren’t thrown, and Mamelukes didn’t hurl scimitars from camel back
So in the grand scale of fantasy, the meso civs aren’t more fantastic than the conventional civs. This game is historical caricature, but the implications in the civ design can be quantified for accuracy.
Britons aren’t an accurate civ since they don’t get paladin despite being one of the most heavyhanded crusader powers, but it’s done for obvious reasons. Just like including Mayans with something more than feudal archers and a mobile cavalry-like unit was included.