There is something that can defeat the big unit of inevitable body guards and the Slann itself. It's a little combo I run with my VC.
It requires one Vampire with the Lore of Beasts (then whatever you want) and of course you'll have the spell which grants +3S and +3A to a friendly character. Step in a vampire lord with the sword of bloodshed, the crown of the damned, red fury, infinite hatred, and avatar of death. Normally nasty on his own, but coupled with the beasts magic buff(s) [plural included in case you wan to go really crazy].
Also get Vanhels Danse Macabre on him if possible, but against Lizardmen it makes no difference (high initiative removes need for ASF). You have 10 attacks, S8, WS7, I7, re-roll all misses every round of combat, AND any wounds you cause come back in the form of additional attacks to be made immediately
. Should anything survive that destructive firestorm, you have a 4+ armour save and a 4+ ward save too, if at the cost of becoming stupid
, but Ld10 is fine for that anyway.
It's a horrible combo, it turns a 20-man skeleton unit into a deathstar all of its own. When it's flanked by a 40-ghoul horde and a horrific 30-grave guard horde with flag of blood keep and banner of the barrows, coupled with helm of command from the beasts thrall, it's just....just.... insane!
Anyway, I went on a little rant there, but the lord combo is really what I wanted to demonstrate here.