I don’t know about that. In ET your right in that soldiers were not that useful in terms of objective as they couldn’t do any but, get a good morta or MG42 or even a flamer on indoor objectices and they can walk through teams. I always remember the old Panzerfaust + Mp40 combo at lvl 4 or Adrenaline + flamer lol.
As for ETQW SD made a good decision in my view in giving soldiers charges so it wasn’t just engineers who did objectives, so they are even more useful. A good hyperblaster/GPMG can literally mow people down and you need Rockets to take down flyers and other vehicles.
Sure you wont have vehicles in Brink but the soldier is still going to have the most offensive minded perks and abilities. You need them to blow up objectives and to hand out ammo like the field ops normally would and the grenade + Molotov combo means they have more grenades.
Don’t expect everyone who plays soldier to run wih the heavy body type, I plan to do that with one of the Heavy Machine guns but there will also be those who go light to blow those side entrances real quick etc.