The jolly part is only helping my case if you're saying that most people use jolly.. Obviously jolly will do less than adamant, (not too much difference, but still :P)
Jolly 252 Atk Mold Breaker Excadrill Earthquake vs. 252 HP / 0 Def Aegislash-Shield: 236-282 (72.8 - 87%)
61.7% of Excadrills...