You can be a reasonably decent player and get 0 medals by being in recruit gear against a full war hero team that keeps you stunned and dead the entire game because you're a free kill, and you didn't happen to get a crit of more than 2k against them in the one shot you had per life to do SOMETHING.
Not all failures in life or in games are due to personal badness, sometimes the other team is just that good.
No you really can't. I'm serious. I've fully BM'd 6 characters at level 50 now and I've never, ever, ever not gotten a medal, except one time that I joined *right* as the warzone was ending before I even got out of the spawn. Either I'm a pro (I'm not) or it's just really not that hard.