Counter to theif skill
I like the idea. At the moment the sword thief is THE counter class to HGH engineer. With your screen version the engineer would be the counter class to thiefs.
5 seconds? How about full 10sec duration? Its a 40sec cooldown afterall, that still leaves a Thief with 75% of the time being invisible.
Also let one of the Turrets fire at stealthed targets, not breaking their stealth, but it’ll serve as a warning that someone in stealth is nearby. Thats sorely missing, atleast in WvW, a way to get a little warning that someone is skulking around.
Similar abilities should go to Ranger aswell. There, the two underdog professions now get a much needed Stealth-counter. Atleast in WvW.