Which is a shame. Because I loved the trash mobs in Labyrinth of the Ancients (Vassago especially). They had mechanics that were present in one way or another found within boss fights.

Poisonous water in trash section and Bone Dragon.
Pads during Atomos (if less than four on pads, then other team can not attack Atomos), Magic Pots during Thanatos (if a pot dies, then one team will never become a ghost).
Bombs during Vassago. Bombs during King Behemoth.
Pads from Atomos and King Behemoth's Meteor were the tutorial for Phlegethon's Ancient Flare.

Syrcus Tower trash teaches the player nothing of what to expect, as they're just Brayflox HM trash mobs.