I've noticed the start of the dog pile is typically not the issue. Often it starts by accident; like two users coincidentally replying the same thing to a third one, seconds apart, because they didn't see each other's reply. I feel like most people would immediately see it and say "nah, coincidence".
The issue is how it keeps going on and on and on. So perhaps this could be addressed by avoiding the pile to grow, instead of just avoiding it from beginning? Basically, different rules for early and late replies.
I'm just throwing ideas in, mind you.
Dogpiling affects even views that are orthogonal to what the mods would enforce. So it's a more of a general problem.