I have a few suggestions for stuff:
poison blow darter (shoots poison darts but they cant pierce armour)
sleep blow darter (knocks out enemys but the enemy that was hit is not dead,it is just knocked out so allies can kill them with eas but the blow dart cant pierce armour)
AP blow darter (the darts are very sharp,sharp enough to pierce armour)
also the darts feathers would be different so like poison would be green,sleep would be purple,and AP would be red.
armoured ranged units
leather armour (50% weaker then regular armour,but resists arrows better then regular armour)
regular armour should resists melee attacks better then leather armour
that's all I can think of for now.idk if your working on the modern spin-off yet,but just in case I'm going to make one suggestion for it (well one unit with variatys)
military jeep (really fast and runs units over)
military jeep with machinegun (is exactly like the first variant but has a machinegun on top that shoots really fast)
military jeep with cannon (has a big cannon on top that has splash damage in a large radius)
and if your not working on the spin-off yet,then you could add it to your ideas list for the spin-off :D