I found this article very interesting. There are many different points to go over. I think the first one would be that Chad himself did a lot of Olympic lifts while he was doing track. I am pretty sure I have seen videos of his athletes doing strongman and olympic lifts.
My next point is that 2 of the most famous trainers right now, Joe DeFranco and Zach Evan Esh are training their athletes using a ton of strongman type stuff. These two guys are producing some of the best results around in their athletes.
Strongman builds overall strength and mental toughness. You can push your body to the limits, and that is helpful to any athlete. In my opinion.