Since I've been running zeta Savage on PH I, I figured I'd throw in my lessons learned, since it's not mentioned elsewhere in this thread. I can't speak to mods except that I have close to all 5 star mods and only one is lvl 1, the other 5 are lvl 15. I only chose to zeta Savage because when I bumped his gear to lvl 10 I noticed I already had the gear (or close to it) to bump him to G11. He immediately became my most powerful toon and I think I've only cleared GW once since I gave him his Zeta like a month ago or whenever it was. So I've never run him at G10 and don't have any advice for people who do. At G11:
I use his basic and ignore the other droids unless grievous makes one of them taunt. If a taunt is up I try to focus down one of them to below 50% to work in Savage's special, overpower, to try to get in a few hits with CC up and CD up. I attempt escape as soon as it's available, unless I just did overpower and have the extra buffs, in which case I hit the boss until the buffs run out, then try escaping. If it fails, I've consistently been able to make a 2nd escape attempt a few turns before enrage, even if I prolonged the first escape attempt to get more mileage out of overpower buffs. If 2nd escape fails, I've always had a turn before he enrages to retreat. It's a bit demoralizing, but trying the early escape improves the overall likelihood of registering damages. Once the boss is below 50% you can use overpower on him directly. Since it doesn't do that much more damage than his basic, I recommend only doing that if none of the lesser droids is close to 50%. If any of them are, get them down to 50% and use overpower on them (if you have it omega upgraded) to get the extra critical chance and damage to use on grievous. Only time I came close to losing him was when the B2 dropped all the heals-over-time right before his turn and he got no healing on his turn and was below 50%. I idiotically continued instead of retreating and he stayed up until his next turn when he promptly returned to full health. I think the B2 buff drop just prior to Savage's turn is a once-in-a-blue-moon situation. Sorry for the wall of text. Composing this on a tablet.