[Finalgenesis]

Agree bow of war isn't too effective on massive shield hordes. Also don't work well with storm. Lightning options aside (It's been well covered)...

Sounds like you have good D/N income, I'd guess an okay W/A income too at least. Probably N access via pretender. Using CBM 1.6 assuming? Guessing no EDM.

Taking into account of the above and that your specific problem is massive chaff horde, econ thug chasis Banes aren't bad. Though if you want to incorp them into lightning strat you'd have to shell out +3A for each... Otherwise 2x frost brand banes cost 4D 4W apiece.

All you need is a S variant of your mage + 3x bane in a stack equipped with dual brand. stick the mage adjacent to the bane stack, cast Luck, ethereal, quickness, xxx(retreat if you like). Your bane stack on hold,hold, attack closest. cost: 24 gems, it should demolish infinite amount of chaff. It's almost exploiting the poor AI as it's very easy to counter for a human, though AI doesn't actively deploy them. You can pile on the LR ring, AMA ...etc if you feel like splurging for anti-banishment and integrating them into your thunder strat. For enemy mages just bring along chaff screens and the like to draw fire. When integrating into army, try to set the doom stacks more then 15 squares away from anything else, to guarantee your mage will cast quickness on the bane stack.

Since you have reliable access to skull staff, a D pick mage with skull staff can cast wailing winds with 2D gems. Yazatas' awe (or anything else with awe, though you can;t forge gleaming shields) should work wonderfully against chaffs with emotions after the wind works on enemy for a few turns.

Edit: Oh if you do plan to use mammoths, do luck/ethereal them to extend their rampaging duration. If you use water elemental, make sure to use it in cold prov (not sure if cold 2 is enough or only cold 3) for amplified effectiveness against chaff (turns into ice elemental, which tramples). Carriers for bottles can retreat turn 1 and the water (or ice) elemental stays in the battle as long as you have a magic leader (anything with mage path) remaining. Since AI don't know how to cut off retreats you can abuse bottles with 2x bottle scouts bring in free elementals to any battle every turn.