>>81687060 (OP)This is only 1 factor but it may contribute:
People with high amount of genes of Nordics/Irish/Slavic/Russian decent can store more fat, especially around stomach, without it harming their health.
A typical African becomes sick and die much faster if they are overweight compared to such Nordic/Irish/etc person.
Strength requires usually both muscles and fat to be highly competitive in such sports. And also being kinda fat for a long time.