As far as SEALs and other special forces level of strength. I can't mention specifics, but I have first hand, on the ground knowledge of just how strong these guys are. Truth is, they aren't really.
There are all endurance athletes. Not powerlifters. Now all of em can do say 20 pullups which is a serious strength achievement, but most weigh under 170.
The real issue is training risk... To gain strength you have to undergo risk in lifting heavy. It costs over $4mil to train one SEAL (at their peak deployable value) , so they are not encouraged to take risks in their weight training.