Fanatics in white, if you could make them look monk like as monks joined crusader armies. Also devout version- so they could be like RoR .
Maybe make them anti infantry but really glass cannon like Witch Elves. Low upkeep, no regard for themselves so they should melt when fighting units like Swordsmen, Spearmen but come out as the victors. Expendable trait, but these shouldn't be stacked as main line due to no armour, very low defense.

Small groups of Crossbowman, with large shields on their backs. Rather than being 90 models, make em like 50 but have quite good dmg. Upkeep should be high on these, maybe tier4/5 - keep focus on archers

Oh yeah I though about monks too and also tomb raiders with pickaxes and shovels

You could add maybe some "heavy swordsman"

for example more armoured ment at arms