I was able to play cat and mouse with those zombies compared to my first character's usual sit in a corner and wait for a strike approach. The trick is to get to those zombies one on one ASAP before two or more of them get the chance to surround you. A Dual wield is very advantageous here. I had a couple of advantages (played at level 59):
1) I had dagger proficiency lvl 1, one hand sword proficiency lvl 2
2) I had dual wield specialization
3) I was using DoSP with a balanced steel sword -- full power of both of them with attack cost of 3 only. Btw, I normally use DoSP with Flagstone's pride. But not for this map.
4) I had cleave level 1 skill
5) Total AP were 10 + 2
6) Corpse eater lvl 1. Nothing significant.
Overall, stats were (nothing to brag about, or even impressive, but was able to get the job done quickly):
ECC: 17% (with flagstone's pride it becomes 25%)
All of my BC was from gears only (no base BC I had) so I had to sacrifice some 25 points worth AC to gain more BC with different gears. I normally fought with troublemaker's gloves with Vacor's boots. But I switched to Globetrotter's boots and gloves of the guardians to prevent angry zombies from eating my 10-15 HP on every hit.
Anyway. Thanks to higher damage per hit, with two strikes (with or without critical) most of the time any zombie was done with. Which means in a single round I could easily kill two zombies and also manage to hit once more on a third one. With high HP and reasonable BC, damage was low and I only bothered about potions when my health fell below 75. Otherwise, I used cooked meat (+3 on every round) to recover and to keep going after them, picking them one by one. Sometimes, getting swarmed too. Hehe!
One more suggestion. If one want to finish graveyard, and don't want to enjoy it, then get your hands on Cave Fern (found in Elm mine). It prevents putrefaction for 10 rounds. Which means with a good offense and a reasonable defense and HP, you can kill the swarm easily, without losing hits because of putrefaction, once you enter the graveyard, and can quickly head for the King's head.
BTW, the loot from the chest is a bit disappointing compared to the efforts it takes to reach His Highness just for a dual with him.