Which class is the most viable for guild wars?

I'm looking into getting into wars, and I'm wondering which class I should go for.

 

warrior and mages because:
1. i don't know
2. still don't know
3. i really have no clue why they're good

 

Warrior and mage because they have hit cool down and heavy hitting high damage melee and spells. Also mage heal. The reason why heavy damage is valued over dps is because guild wars has a gimmic where you can’t damage the tower immediately after you hit it, which makes it so classed like archer and assassins are out of the equation. I have no idea why heavy melee assassin isn’t a thing in wars

 

if I had to guess its because melee items usually have no agi or -agi and assassin base def or weapons don't give as much raw health or defense