I don't do SM anything, so I just figured I'd throw in a quote from a Q&A w/ Louie Simmons found here.
Q: Coach Simmons, how do you recommend one train for strongman? Thanks so very much for your time and consideration.
Louie SImmons: We had a strongman visit us not too long ago. He trained the same as our powerlifters with respect to the core exercises. We had him do considerably more GPP work and varied his accessory training using some strongman specific movements (ex. Overhead presses after his main bench exercise).
With weights, the bulk of his training was with low box squats, good mornings, deficit deadlifts, and band pulls. We took him from barely pulling 500 lbs to 800 lbs! We did not train deadlifts for reps with our view being that absolute strength will provide the strength endurance needed for his meets. In other words, if you can pull 800 lbs for a single, you can pull 700 lbs for reps. Conditioning should come from GPP, not the weights. This is ALWAYS true and I cannot emphasize it enough. Weights are for absolute strength and GPP for more generalized endurance.
We skipped powerlifting gear with the exception of briefs. He would not be competing in a suit so we felt that training with one would serve no purpose.