Its complicated. Ultimately the Factions should be the real danger because of "better strategic AI" the ability to build, maintain, and improve cities, and of course all that juicy MANA!!! 
Even a deadly army of pack drakes backed by a few fire breathers would eventually crumble to a united onslaught by a magical empire.
Still, its something that should have the potential for danger at any point in the game I think, not just as early game stepping stones.
Although .... this is probably just a different setting, or a different game/expansion that would cause this.
Its not my primary focus/concern though. Monsters as they are would be fine for Gold/Launch imho (other than LAIR guarding, better LAIRS in general- aka multi levels, and possibly Text Based adventuring ... which has everything to do with the Neutral Faction).
The only thing I REALLY want is for the Shadow Demons (from the Shadow Gate spell) and Waerloga's dragon army to spawn more as factions than as an army that does nothing.
^-those two epic end-game things are the only stuff I'd really want changed (as far as Neutral faction is concerned) for Launch/gold.
However, I'd still rate priority on Waerloga and the Shadow demons as only a 15 or a 20.
For me, Faction Differentiation is still a strong 98 or higher, and better AI is a steady 97 or lower.
---> If its true that "pioneer armies' are due to the enemy factions not having enough unit designs, then DESIGN TEAM BETTER GET ON THAT! I'd label that as a 75 importance as its a mix of AI (97) and Tactical Battles (45)