Geo Spy was my hero in Tier7 of that event. I don't remember how tough Tier5 is, but in t7 my spy was still only g9+something.
Dooku can be helpful, but what you really need from him is Shock. They're going to cleanse a bunch of things right away so it can be useful to wait until Dooku's 2nd turn to inflict shock, unless Padme's squad has a bunch of pre-loaded TM (I forget that, too, maybe I should replay the event for info). Then Padme will have used her cleanse special already, so it's probably okay.
AV is the most useful toon there other than Spy for this event. I'm also someone who relied on AV solo for this event, and she has to have her Rampage zeta, but you can't remove Padme turn meter, so Ventress Lead zeta won't help much at all (it will only help give TM when falling below 100% health - which with the right RNG can be great, because you get his, then you hit back and health steal puts you at 100%, then you get hit again, etc... but it usually won't work out well for you b/c usually your health steal isn't enough to get back to 100%).
I think out of that group, I'd probably run Ventress, Dooku, Poggle, Grievous, Spy.
Spy hits incredibly hard against all those buffs. Poggle is geared enough to survive and then buff your damage dealers and maybe land some Ability Block (target these at Kenobi and Padme early).
Grievous takes no out-of-turn attacks, but if you can zeta him, he still gets bonus turns with mass damage He'd be like your side's Anakin...again, IF you zeta him. Grievous also stuns and inflicts healing immunity which are both very helpful.
If you have any gear to give, I'd give it to Spy, Grievous, Ventress in that order. If you have a zeta to give, I'd give it to Ventress first, Grievous second, Dooku third.
As a strategy tip for what to do during the battle, I'd say don't be afraid of using Ventress' dispel as her first move. It's probably even necessary. Then I'd say to remember that the only 3 toons that are true problems are
1) Padme
2) Anakin
and
3) the Jedi that brings people back from the dead.
Once those 3 are dead, the rest is easy. The Reviver has more health than you expect, and it can be hard to whittle him down. Using Spy against him is probably best. It's also really hard to whittle anyone down while Padme is still there providing bonus protection. But it's Anakin who is going to kill all your toons, especially is you're killing other toons while Anakin is still alive. So different people have different ideas about who to kill first - the most popular is Anakin, Padme, then Reviver. But on my successful run I remember killing the Reviver first, then Anakin, then Padme. Other people had the best luck killing Padme first.
What do I learn from that? I learn that the best strategy is probably an opportunistic one. Killing Anakin is worthless if he just comes back from the dead. Trying to kill anyone is worthless if they keep getting more protection while you're trying to kill them. Killing Padme or the Reviver is worthless if as soon as you kill them, Anakin AoEs your whole squad.
So instead of trying to follow a rigid schedule of which one to kill first, I'd stick to those three, but focus on whichever one seems the most vulnerable. Be flexible and willing to kill any of the three of them you can, whenever you can. While doing that, though, try not to bounce people under and over the 50% health line. You want to take someone from green health, but less than 100%, down to dead in just one shot. Ventress is the one that can do that for you reliably. Spy can do it easily with his special, but it's much harder for him with his basic. So really only go for the kill shot with the special UNLESS ANAKIN IS ALREADY DEAD. At that point it doesn't matter if you make someone's health yellow first.
Tonight I'll replay the event just so I remember what it's like with more precision, then I'll come and write a little more. but it's going to be really hard for me to give perfect advice since my toons have so much more gear on them. I don't think I have any separatists at all that have gear 11 or less. Everyone is g12 or more. Except Wat Tambor. And you don't have him, so...
In any case, I'll do my best to gather some more info. Best of luck.
