Lowering your opponents stats in vgc is usually not that viable, however, let's see. The thing with charm is you usually aren't going to have two physical attackers on the field. You usually have a sweeper and a redirector, a physical and special redirector, or like trick room setters or a support mon. Charm is much more useful, and is quite common on raichu, one of the more common support 'mons. Growl is useless because of what I said before. While baby doll eye's priority is quite useful, again, it only lowers the attack by ONE stage. Thus, I like to go with charm. It's like eerie impulse, which is much more common than spatk lowering moves (moves that do specifically that purpose, not like moonblast)