When you set the promotions for the normal Registered Usergroup,under the Promotions option,in the very 1st option,it states which usergroup is going to be affected and the last option states which usergroup "Guy" is going to be get promoted to if he hits the promotion strategy you set.So in this case,as long as you dont set any promotions for the new usergroup - "Men",it wont affect the usergroup promotion strategy you've set for the other Registered Usergroup.
Hope you understand what i'm saying!Cheers!