Tackling is a perishable skill? In football? It's a required skill that's taught in middle school or earlier.Many sports involve perishable skills requiring practice to maintain full proficiency.
All of these guys know how to tackle opponents with similar size, speed and athleticism. When the opponents measurables are better than their own....that's where the problem lies. The RB for Duke was the best athlete on the field and we couldn't tackle him.