Hmm, maybe I'm not fully understanding aspects placed by maneuvers. If it's a fragile aspect, once it's tagged isn't it removed? Wouldn't that allows another of the same aspect to be placed on the target?
An aspect isn't fragile by itself, it only becomes fragile if you tie on the maneuver roll.
The fragile part should be represented in how the aspect is phrased. So if you aim for a "shot in the foot" aspect but you tie, you should change the aspect to something like "a jump to the left" or "bullet dance", to represent that it doesn't last too long. Those aspects last only a very short time, and should be used right away, or they go away. But once you are shot in the foot, you are shot in the foot, that's going to stay around, so making an aspect like that fragile seems off. Since it isn't a consequence, it won't exactly stay along after the conflict is over, maybe you just grazed him, and it was worse in the moment than it actually is. The fragile aspects above, however, can easily be justified to go away pretty quickly.
Then there's kind of a diminishing return on shooting someone in the foot, I think. It's going to hurt like hell when you do it the first time, maybe the second time, but after that, it kind of becomes silly.
Maybe something along the lines of "distracting shot" would make more sense. It would still be the same for the most part, but it doesn't involve actually hitting and hurting someone, since that's more the area of consequences.
Coming at it from another angle:
I've used a sort of bonus tags thing in the past, when a player had a spectacularly good roll. I would let him choose to take an additional tag for himself, or he could get 2 additional tags, but he would have to give both of them to other players. Since you want to go for a supporting roll anyway, maybe that's an option.
Distracting Shot (Guns): When providing covering fire or drawing someones attention, you may give up your free tag on the aspect and in return give 2 free tags to other players.
You wouldn't be able to use it yourself, you would maintain your supporting role, it doesn't mess with wounds/consequences. All in all, it may be a more elegant way to go.
Bonus points if another character who is regularly working with you takes a stunt that allows him +3 instead of +2 when invoking these aspects from you. That's going to make for a killer combo.
