As a musician as well, I would compare it more to saying that I'm a drummer and should learn a little about guitar, piano, keyboard and bass. That's not always the case. I've shot a bow and crossbow but I haven't picked one up in a very long time. If I were to to spread my time equally or even semi-equally among all possible missile weapons then I would end up the jack of all trades and master of none.
I think Top Shot should pick folks who have a RANGE of skills. Right now it seems all the folks there are 90% pistol/rifle folks - they should have some exhibition shooters, bow shooters, knife throwers and the like, this way one person can prop up the team during their specialty if others struggle.