Useless or redundant units?

[B0rsuk]

Let's assume the 2 units are 10 gold 20 resource each.
And the 20horde is 10 gold 2 resource each.

20horde is 200 gold 40 res.
2 units are 20 gold 40 res.

20horde consumes 10x as much supplies.
20horde costs 30 upkeep per turn.
2 heavies cost 3 gold per turn.
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There should be a global enchantment that makes each unit cos -1 upkeep (gold). It would make quite a difference for hordes.