Note that both Agincourt and Dupplin Moor involved large forces attacking a strong defensive position on a congested battlefield constrained by terrain.
At Agincourt the English positioned themselves on a narrow area of open ground between two woods, while at Dupplin Moor the Balliol faction positioned itself at the head of a narrow valley. In both cases the terrain effectively funneled the attackers into a kill zone.
These circumstances might feasibly lead to great piles of dead as the soldiers at the front of the attacking force could neither turn back, due to mass of advancing men behind them or spread out due to configuration of the battlefield.
Note that in the battle of the bastards a small attacking force charges across an apparently wide open plain. The circumstances required to create heaping piles of dead appear to be noticeably absent.