Sure offensively they can fire off a barrage with a single click, but they can not react or move effectively to defend themselves to someone who employs or uses knockbacks, aoe silences, single target pulls or movement snares to disrupt the multi target broadcasted clicks.

 

If the multiboxers characters are not all exactly in the same spot, they can not move or target effectively with the broadcasted commands and they are an easy kill as the individual characters will be clicking randomly elsewhere on screen. To gather all the characters back into Albion Online Power Leveling position the boxer has to individually command them back or try running all his characters back into the same corner to align targeting.

 

Here's to everyone who was gotten free coins from Samdaman Deathwalker and akin "professional" multibox pvpers!If the only reason would be extra bank space and you want to allow it, why just not make more space in banks? There would be no reason to use multiacc.