Thats not a synergy but a combo i believe
Why would it be a combo. You can use those two skills apart from eachother perfectly, but when you use them together they give a larger benefit. Or am I not using the right definition of synergy and combo in game terms?
And about Guild Wars, the consant updates are part of every MMORPG (although Guild Wars is referred to as "CO-RPG"). Overpowered combinations can be a problem for a single player game, that's true.
(I'm not going to give my thoughts on what you said about the 55-build to keep this thread clean from in-depth discussion about other games