The meta of people playing BGs on both factions changes every day. I always tend to win more than I lose, being that my geared multiboxing teams easily slaughters everything that isn't both geared and playing as a team, but beyond that, I've had days where I would just be getting bored murdering teams of 200-400K health idiots or even watching the rest of my team do it without even needing my help, while other days, even my 4x 550 DKs or ~540+ shamans weren't able to carry absolute trainwrecks of horde teams.
By the way, BGs are cross-realm. You're fighting the same people regardless of your character being from fun or 100x.