Supporter groups gain reputation through action...not logos and motos. Yes you want to have a logo and motos you can be proud of but you also want them to represent who you are and not what other people are. There is a difference between reputation and image. Mobsters didn't gain their reputation by wearing images of brass knuckles on their sleeves. Im not trying to knock your motive to come up with a symbol that represents strength. I'm just saying that if you do want to be suggestive there are ways to do that while at the same time appearing more discreet.