As a former Olympic weightlifter, I look at the strongman sport in real awe! You'd think I'd be biased towards weightlifters as being the strongest; however I simply cannot go beyond the sheer strength (or rather raw strength) that these strong athletes possess. I can tell you right now that it's a whole lot more difficult to lift an Atlas Stone than it is to perform a clean & jerk!
In the sport of weightlifting, endless hours are spent on perfecting the lifting technique for one purpose and one purpose only: making the lift easier. So for me right now, (until someone can convince me otherwise), the strongest athletes or the sport that calls for an all-rounder of (sheer-strength/endurance/power) would have to go to the strongman sport/athlete.
Fadi.