I don't think it's a matter of being a hunter. Each of my clan's runs have been with three hunters, and technically we five manned Templar the one week without cheesing (which actually isn't saying much, but still serves the point). Hunters make great relic bearers due to speed. More importantly, if you spec this way, as a Bladedancer you have stealth revives and a way to pull yourself out of emergencies by stealthing. Its use may be halved in hard mode since you can't revive, thus only being able to stealth yourself, but the ability goes a long way. Gunslingers have an awesome priority target waveclear (depending on how you spec goldengun). More importantly, the abilities and your class supports you in a game that is still about shooting first. I think a lot more people realize that than anything else; it may have more to due with level. A lot of 24's and 25's try to go in but suffer too much from dealing reduced damage and taking more damage to be successful.