Please explain edge formation's effective or need to provide more for edge formation

I know the line formation can cover flanks to stop flanking calvary to deal dmg to skirmishers and loose formation to use to avoid taking heavily aoe damaged from mangonels, but what is exactly wedge formation does? I merely see any advantage at wedge formation, or need to provide more effective for it?

Edge formation in my last map got bug locked on… i had a hell of a time flipping through them all trying to get it to stop…

Wedge formation is to essentially punish moving units. It wedges (hence the name) through the enemy formation. instead of just hitting them head on, it kills them from the inside out. It’s essentially for unit targeting and can reduce casualties on your side. I’d recommend to use it with cav only.

Wedge formation seems completely useless without it giving some kind of charge bonus or something. It is the exact opposite of how you want your units to engage. You do not want your units fighting from the inside out, that gives all the advantage to the enemy. It is much better to surround the enemy in order to maximize your DPS and minimize theirs.