Salamanders. 2-3 units of 2 will roast skaven hordes, not to mention the panic tests when suffering casualties.
Removing rank bonuses is more important on skaven as they also get +1 ld for each point of rank bonus they have.
And Flaming Weapons. Those hell pit abominations don't go down easy. Flaming attacks make this task much easier. There's the Burning Blade, and the Banner of Eternal Flame. The Banner can be given to Temple Guard or Cold one Cavalry, or your BSB can equip it and confer the flaming attacks to himself and any unit he joins.
If I'm right the banner makes all attacks flaming, not just CC (need to check that). I'd like to see how a Skink Chief on ancient Steg with Banner of Eternal Flame works. 4D6 flaming poisoned shots from the giant blowpipes, 2 flaming blowpipe shots from the chief and 4 flaming javelin shots. That's an average of 20 flaming poisoned shots.
Also watch out for long range weapon teams. Take some chameleon skinks to scout them out (can deploy in LOS now, as long as you are 12" away). With a 12" march and shoot move you can get them in a good position to take out the warp lightning cannons and jezzails. Terradons would do a nice job of this too.
Finally, I like to use crown of command to make a character (and any unit he joins) stubborn. If you're faced with a horde with way more ranks than you can match (highly possible), you can then reform your unit to match their frontage and maximise the Saurus' 2 attacks without worrying about loosing static combat res