It could be risky for the dabbler, since I don't think a mere dabbler could stand a chance against someone with a full magic attack bonus, but as a group strategy it could work well, because if the dabbler actually manages to engage his opponent is a WOS, the other guy is just standing there trying to shake the soul attacker off, unable to act, and he would be very vulnerable to other attackers. Most dabblers (aside from scholars, nobles and temptresses) will have a low will save also, so it would be hard for him or she to actually drag someone with a higher will save into the WOS. That is if I remember the rules correctly, as I don't have the books at hand.
Another big disadvantage is if they actually lock in a WOS, the dabbler most likely will have a few PPs, so he could be drained quickly, and then his wisdom would go next.
What is unclear to me is what kind of action is to attempr the WOS, or to try to defend against it. If defending against the attempt soul grapple is a standard action, then the defender would still be at a disadvantage, because that would prevent him from taking other standard actions. The only option he would have left is a move action. Again, if that is the case.
