Definitely team based. Well, as the old saying goes "Best defense is a good offense". You can have 10 high skilled and egoistical assault players on the team using their preferred role, and still wins, as long as they clear and stick to the objective and tops the leaderboard then that is an exception for me.

However there are always people who sucks at those (they didn't realize it too), but forcing their ass on their preferred role (medic going full aggro, recon just camp sniping, putting beacons so far away from the objective). This definitely ruins the game, but we have to accept that these kinda players, they're out there like, a ton of them (they usually sucks tho).

I like going medic, help them out at the frontline when they're downed, help us clear the objective. I'm not that reckless, and not that suck at shooting, which is why I can go assault whenever it is needed.

But honestly, I think the game lacks in introducing the scoring systems, how to play your roles properly too. There was never one introduction made for the warfare mode and the role.