One way to immediately balance some of the problems created with things like the Warrior (too powerful) or the Ranger (too weak) would be to have different tiers of CC based on the overall squishiness of the target.
So. . .
There would be three 3 tiers of targets facing crowd control (NOT damage conditions as making the warrior subject to all conditions made them useless in the past). One would naturally get 40% longer duration. Most would get zero change. The final tier would have significant natural resistance to crowd control.
This is done based on the class’ mechanic. A warrior should be offensive with a real knack for getting slowed down. A thief better avoid cc with stealth or else. On the other hand a guardian is well defensive by nature and the ranger just plain needed the help (and is the guerilla skirmisher you can’t slow down easily).
+40%
Warrior
Thief
No Change
Mesmer
Elementalist
Necromancer
Engineer
-40%
Ranger
Guardian