I think its a gimmick because you're substituting "combat engineers" for actual front line infantry. its unconventional tactics
kind of like vetted pio spam, which was gimmicky
satchels are situational anyway, a smart player wont bunker up once they see you crank out a few sturmovie. just like im moving my pak away from the thrown satchel. and suppression resistance only goes so far against a few MG42's when you dont have the main line infantry support you should have
but this of course is all theory craft