sigh,who said demo charges are terrible... Assualt engineers as a combat unit are straight up terrible,as they take damage from simply existing.
They are essentially USF Ass grens, good early game and fall apart later in the game due to escalation of DPS and removal of ability to close. Of course none of this matters when the most powerful explosive in the game can be put down by them which gives them something to do at the very least.
Also they blow up a lot less now since the flamer changes, also will probably get better this coming patch with the new anti-garrison changes.
and even if it wanted ass engies strictly for demos,which is stupid really in itself with how strapped USF is for MP/upkeep/muni now,id just go armor and buy the engineers when I have excess muni and manpower for demos. In other words,as a luxury when Im already winning.
Most people keep Ass Engines strictly for demo's. It's been par for the course now for a long time. This of course high lights the fact that they aren't disireable purely for their combat traits.
Them being in this doctrine is a total afterthought
This describes about 80-90% of the design choices when it comes to WFA factions.
Also funnily enough there is an M3 HT in the game files with 320 health, 8.4 armor, and much cheaper cost so they could actually just swap that in and fix everything (plus still add the new vet 1 thing because it's cool)