I had great success with Light Armour + shield + hand weapon for parry save. Crown of command dawn stone dragon helm, for a 1+ rerollable AS, and 6+ parry. for 231. this allows me to field a bsb life slan, making the slan almost invincible. stops opponent's deathstar unit, allowing my army to rampage, and once it's done finish off the deathstar.
Here is a build I would take at 2.5k; Old Blood w/Sword of the Hornet, Talisman of Preservation, Dragonhelm I could chuck other gear onto him but I have to keep him cheap so I can fit in the Slann. ASF with his I4 isn't too bad, he already has plenty of S5 attacks, and you have 3+/4+ saves. For people fielding a cheaper Slann (or none at all), I'd chuck a Potion of Strength onto him and a Cold One mount. Save the Potion for when you face down a monster or hero, just carve up regular infantry until them.
I quite like tooling mine to take some cavalry with him and go Hellpit/Hydra hunting (flaming attacks to mitigate their regen for the phase, and mounted to avoid thunderstomp). The main drawback of cavalry is their lack of ranks, so stubborn is a must; Old Blood on Cold One with Burning Blade of Chotec, Light Armour, Crown of Command and Talisman of Preservation. 1+ Armour Save, 4+ Ward Save, Stubborn, 5 S5 Flaming Attacks with a total of -4 to enemies Armour Save.