Generally speaking if you want to solo offline raid or are trying to make a small hole in an enemy's defenses to sneak in you'll either want a stego, reaper or bronto to soak one side of a base/portion of a wall. That's assuming if you can't find any holes to exploit (most tribes after a certain point get lazy with their defenses, keep prodding for that weak spot like an exposed wire!)
Golem is useful in the short term but not really for a long term base soak, you can still get shot off pretty easily from it. Mixed results from using one, stego and boxed paracer is all around safer. For longer engagements or straight up base sieging you want multiple brontos with boxed platforms to defend the rider, and paracers as a sort of "boarding ship". Essentially, you stick out 3-4 foundations from one side and walk up to the wall of an enemy base, and place C4 onto the wall through a window/frame or door at the end of the foundation line. Granted, it'll be difficult with server lag, and defenders sallying out to eat your tanks before you get close enough to do this but if your tribe is aggressive enough it works.
Once again, Brontos are still good for brute-forcing your way into a base, just chuck them onto a wall to soak all their bullets, but a paracer/stego is equally viable for small teams going on griefs or meatruns into a lightly defended storage base. The key is timing. You have to plan EVERYTHING out beforehand. Tribe up your members several days in advance, space out the join times so it doesn't seem like you're up to anything. The alpha won't think twice about it unless you've been blabbing your mouth on community discords/forums to the point where they recognize your name. Afterwards, grab a flyer, scout around (preferably at night, use NVGs to scout out the base). if there is an alpha on the server, chances are the caves on that server are used more or less as storage, so those might be worthwhile to check out first if you're griefing, actual bases if you've got a competent group/big raid planned. Another note is that caves are slightly more easier to soak, since you're less likely to get noticed while doing so in comparison to being out in the open at a large base.
I CANNOT stress enough the timing. You're on a race against the clock when you and your delinquent tribemates join that server. You want to be able to break into the base BEFORE the tribe in question notices you there (if you're going for a grief), because the moment they hear their turrets getting soaked they might be inclined to check it out. Raiding this is less so an issue, since it's basically who can wear down who the quickest (assuming no foul play is involved, which is highly likely to occur).
TL;DR:Golems/Stegos for small team soaking, Paracer/Bronto for large scale soaking. Most importantly, PLAN AHEAD!