I don't remember...
... the last time I saw a fight where one of the combatant's buddies didn't pile in.
On a similar note, I'd estimate that at least 1/3 of the armed robbery articles I've read in the past several years have involved at least 2 BG's.
I'd consider a Taser as desirable a primary as a single shot or double shot derringer. IE, not very.
OTOH, Pepper spray comes in relatively compact containers, and would make a viable alternative/secondary weapon to a primary handgun, where spray is legal.