Maybe there is a way to limit the stun-time? Would need some experimenting but decreasing the stun-delay just by 25% could already make a noticeable difference. Removing it completely would be unfair cuz everybody gets hit-stunned after a melee-hit.
Besides, killing as archer is already not that easy (damage-wise) but with the hit-stun from an archer they are mighty useful as support. Unfortunately most archer don't understand themselves as support.
By promoting a general more teamplay-based game, a lot of balance could be achieved with the settings in place.
2h-hero engages in fight 1v1, a 2nd enemy joins the fight against the 2h-hero, archer sees outnumbered 2h-hero and shoots the guy with the highest distance to the 2h-hero and stunning him, 2h-hero realizes stunned opponent and places a wtfpwnlolstab in the face of stunned opponent, teamplay repeated until WIN...
Unaware crossbow-man is reloading out of cover not realizing the approaching lancer in his back, archer sees approaching lancer, places an arrow into lancer which cancels the couch/hold-stab, crossbow-man gets bumped instead of killed, repeat until WIN...
Sometimes you can see those situations happen but most of the time I have the impression it's more by accident than by actually trying to help the other dude.
One can dream...