To anyone who goes in w/o a BLM like we did, I think I MAY have something that could be quite helpful...
After you get Zeid down to 1/4 HP, you get a cutscene and Volker joins the fray. However, we always took the 60 seconds you have after the cutscene to rest up and regain as much MP as possible. If you just sit there and don't move towards Zeid, nothing will happen. After about 60 seconds though, Volker will move towards Zeid and you will have to re-engage. The first several times we did this (keep in mind we did have a win on our 3rd try, but Krono DCed and we had some other people who needed this so we had to go more than once anyway) I would use Provoke on Zeid and then Flash. However, I began to notice that Zeid would immediately start the second stage of the fight with Ground Strike and it at least half of the time it would hit Volker even after I provoked. I guess it's kind of like how Goblin Rush will hit whomever the goblin was attacking when he started the WS regardless of whether or not Flash or Provoke went off during the animation. So the last 2 times we went in and won instead of using provoke, I would throw up a flash as soon as Zeid started to move. In the end, this saved Volker about 600-850 HP and we were able to keep him alive much more smoothly.
And for those who ask how Volker could steal hate...Well I spent a good portion of the second stage of each fight kiting Zeid to avoid Blood Weapon and also to keep the AOE sleepga WS off of the mages. Thus, I wasn't gaining a lot of hate from Enmity + Attacks. Also, the fights only lasted long enough for 1 Sentinel timer and 1 Rampart timer. I almost always got to use 2 Defenders though and I would macro in Sword/Shield to use a Shield Bash when I could. I went in with Earth Staff primarily to negate the damage from Zeid's WS and to save the mage MP for Volker. As a 69 PLD, most of Zeid's WS would hit me for an average of about 200-300. Now take all of that and combine it with the fact that for some reason Volker loved use Spirits Within on our runs and you have the reason why I lost hate a few times to Volker. The really frustrating part about the whole thing is that just about every attempt where Volker died, we had Zeid down to just a sliver of HP left and Volker would manage to get himself killed.
All in all, it took us about 4.5 hours to get 8 people Rank 10. I give it up to the Japanese DRG, RDM, WHM, and to Genjuro (THF) for all staying for SO long AFTER our first win (which I was also a part of) to keep trying so that Krono, Flik, and Aldowin (who had to log off before he could get a win) Rank 10 as well.