Thief considered as a pet after patch so he takes more dmg than intended.
10,000 strike from normal atack seems a little bit too much to take.
Here (https://forum-en.gw2archive.eu/forum/support/bugs/Ranger-pet-take-too-much-damage-after-patch) players are discussimg about pets taking too much dmg.
Here https://forum-en.gw2archive.eu/forum/pvp/pvp/12-8k-warlock-hit-I-am-clearly-the-best/first#post3940815 players proving thief is taking too much dmg from mesmer minions
I play hief and i must say simple normal atacks from warrior deal tons of dmg. Much more than previus game build.
Next, I saw somewhere here in forum the link to the film, where streamer gets killed by guardian in two shots. Insta kill. 17,000hp down to 0,000 in less than 0,5 second.