2 turn CD would be great but removing the health loss seems unnecessary seen as you can build a comp without it. So far my experience with Zerk Sven in arena is if you drop the Drake between BK Leon, SW Kahuna and Berserker Sven the Drake will wipe an arena team. Change that to 2 turns and you've just made it a lot easier to get to this point in arena. However I can see how removing the health loss would mean you could use him in more lineups...
Svenzerker will be really strong if you return him to his pre-nerf but I think he won't be the best hero anymore with so many powerful heroes with fast CDs/good auras. Given the choice of Sven and Rhea, I'd prefer Rhea since CC is really important in whatever scenario you find yourself in. I do think the CD should remain 3 and remove the pet recoil though since having a bazooka at the end of turn 2 is kinda terrifying if you are not the user of the bazooka
