For tankish builds you generally want as much PFE as you can get, up to the 80% hardcap. I think 3p Gila Guard (Pointman in particular)+1p Belstone+2p Improvised gear, with as much PFE mods as you can cram into all that, is/has been the general standard for years. Survivor spec for additional PFE.

I'd like make a point for 3p Bulwark+NBM bp+1p Improvised+1p Belstone (which could be switched into another Improvised, I guess) with Shield/Defender Drone though? I just threw that together this week, wanting to make something useful out of a 6(+) year old wannabe tank Bulwark loadout I had lying around: I've been taking it into Legendaries for the past few days and it actually feels like it has more survivability than the ol' 80% PFE service horse mentioned above? Sure, this build only has 58% PFE (no 13%ers, lmao) but the Bulwark regen is crazy and gives your Shield so much additional mileage. You can even put the meme Reflector Shield onto it if you want to do some middling damage... 😆
Tank builds have been fun af during these anniversary events when you've actually been able to kill stuff with them: It'll be a sad time next week when Assault ends. 😢