Aggro Tauntgryn - Fitz's H40 Tested Builds
 Ogryn Build - Warhammer 40k: Darktide 

This is what I'm running for Tauntgryn without Slab. I'm still experimenting with the blessings on the Cruncher, but 'Unstoppable Force' is probably mandatory because, quoting Kuli's fantastic blessing guide on Steam, it "allows partially and fully charged heavy melee attacks to bypass Carapace's built-in aborts_attack mechanic so that Carapace armor can be cleaved." For the longest time, I thought only fully charged heavies got this benefit, but no. 'Limbsplitter' is another interesting choice but unfortunately I haven't found a way for it to 1-shot a H40 crusher with the special attack overhead, even with max everything, so it's currently not worth the opportunity cost of losing Unstop Force.

If you're running traditional Slab, swap 'No Stopping Me!' and 'Implacable' for 'Too Stubborn to Die' and 'Brutish Strength'.

Another fun variant of this build is the Bully Club slap build where you spam the special slap, but I'm not that hipster about it. If you're more traditional, I still recommend Slab (dump Cleave Damage) with Flak + Maniac and Last Guard + Skullcrusher. For more tanking, swap Skullcrusher with Confident Strike, for slightly more damage, swap Last Guard for Brutal Momentum.

As for blitzes, Rock still has good value. Its big benefits are stunning bosses and 1-shotting some maniac specialists (flamers & mutants) regardless of where you hit them, their HP, or modifiers. However, I'm running Frag Bomb more and more because of the Rituals modifier in Havoc and because most classes tend to run regen blitzes, so grenade pick ups go wasted. Bombs Away is usually worse than Frag in most cases.