Thoughts and questions...

[Watchman]

That suppression-o-meter sucks, then, except for the slowing down bit. Humans instinctively bunch together under fire, but that's actually the exact wrong thing to do - dense masses are only that much easier to hit. The correct solution is to open ranks instead; more of the projectiles will meet empty space between the warriors, each individual has more room to duck out of the way, and the whole bunch can move faster to get to grips with the ranged troops. (There's a reason the Athenians ran for the last circa hundred meters at Marathon.)

Of course, opening ranks is suicide if there's heavy cavalry in strike range which is specifically one reason the nomads liked their cataphracts - the heavies forced enemy infantry to keep close order, making the archery that much more effective.

Something of an exception is a testudo-style "shield fortress"; it requires rather large (and preferably rectangular; smaller shields simply don't give enough cover) shields and highly drilled troops to pull off, doubly so if the unit is to be able to maneuver effectively nevermind now go to the offensive. But then, that sort of thing is specialised formation designed for missile protection rather than the reflexive and counter-productive bunching up troops are prone to anyway.