But the M10 is openly described as being intended for taking down fortifications.
M10 Booker - Wikipedia
en.wikipedia.org
The M10 Booker Is the Army’s New Mobile Assault Gun
The Booker will bolster the firepower of paratroopers, light infantry, and other tankless troops.www.popularmechanics.com
Sounds to me like they wanted a bunker remover.
They have a range of about 1 to 2 kilometers and lob a propane cylinder (or in some cases, water heaters!) that is filled with enough explosive material for the resulting shell to be three-quarters explosive by mass. Even the smaller ones were putting 60+ pounds of explosive on-target, with some of them going all the way up to 400+ pounds of HE. Their CEP is actually not very large at all; the makeshift shells often have welded-on stabilizing fins and it's not uncommon for them to hit within the same few-meter circle when firing a volley. Even the most inaccurate ones can still consistently pound the same building over and over from a mile away.
I wasn't thinking about the specifics of the improvised mortars themselves, though, but rather their effects on target. They just utterly, brutally demolished whatever they hit, collapsing multi-story structures with ease, blowing facades away, annihilating cover. That's a nice capability to have.
Gotta admit, seeing this is making me glad the GLA is fictional: With all the shit seen in the Middle-East, Ukraine, and Syria in recent decades, there's a hell of a lot of inspiration for them, lol.
I mean, fucking propane canister/water heater artillery? Actual cannon balls? Generals was supposed to be a fucking parody.