As long as there is no stealth It will work. Imo stealth mechanisms end up being gamebreaking at pvp in several games. GW1 followed an interesting model for the assassin role, shadowsteps and high speed, which basically focus on what an assassin in game should work. Get in, kill your target, get out fast.
Emphasizing in why I am against stealth allow me to bring this simple analogy. Rock(plate), paper(casters), scissors(assassins). Paper kills rock, and scissors kill paper, but rock who should kill scissors, can't. Because rock can't find scissors .