Here's my personal ranking based on experience:
1. Mage - Nuff said. High burst damage, mobility, accuracy, a fkton of disables (stun, mute, slow), and goddamn tanky too.
2. Xbow Knights - Unkillable by any physical class alone, but can kill anyone since they have DOTs, long range slow, and a guaranteed stun. It has been shown in the recent 3v3 how they're a menace with 3 taunts available to one knight.
3. Full support Clerics - Immortals, sometimes tankier than a knight. 3 people might not be enough to bring it down.
4. DOT/Dual Raider and Bow Scout - This one is really where it starts to balance out. DOT/Dual raiders are better in duels and falls off a bit in group PVP since they can't output damage as fast as other classes and the DOT gets dispelled easily in a group fight. Scouts are better in group fights cause of the mobility, range and high burst damage, but they do suffer from low HP.
5. Melee Raiders - Debuffs and DOTs are a nightmare to this class, they need to balance stats like accu, speed, survivability, and damage since they need to get up close with the enemy. They output nice damage but don't really have ways to chase around high mobility classes without sacrificing a lot of stats in other areas. Knights and clerics laugh at this class since most of their damage are negated by the former's block rate.
6. Melee Knights - Its counter part is just different. It suffers the same curse with other melee classes in that they have to get close. A menace with a focused healer, but really a bit underwhelming compared to xbow knights.
7. Bourgs in general - Gun bourgs have high single target damage, while launcher bourgs can wipe an entire team grouped up together. Squishy af tho, will need a cleric or two to have a chance of surviving.
8. Artisans - high damage, squishy af. A nightmare in duels since the DOT will take out 2/3 of your HP while asleep with their long ass sleep.
9. BC - A bit underwhelming, moderate damage with above-average survivability. Stick to being FS please.
10. Xbow Scout - Good in duels, that's pretty much it. No camo so very vulnerable to non-melee damage.
11. Champs in general - Food in group pvp. A bit better in duels, but still sucks a lot.