Justice is a fan-made global mod.

The growth increases due to health loss, if you haven't noticed.

I didn't notice; if that's the case, then this change might make sense.

And if you haven't noticed, there's actually logic behind it. Skeleton archers become a complete analog of regular skeletons, only they shoot.

Okay, let's look at your mod:
Elder Gremlins. Attack 3(+1), Defense 3(+1), Damage 2-2(+1 to min.) Health 6, Initiative 12, Growth 20
Bone Archers. Attack 1 (0), Defense 2 (0), Damage 1-1(-1 to max.) Health 4, Initiative 11, Growth 25
Where is the logic here? +25% to Growth doesn't compensate for the worse parameters, and the damage is twice as low.

I had incorrect information about Bone Warriors; I think the 1-2 damage is more balanced for them.

P.S. No offense, balancing is a complex task; as you requested, I'm just expressing my opinion.