Great ideas
I don't have a lot of time to comment on the individual units themselves, but I like many of the units' flavor, like warhounds, slingers, etc.
One suggestion for the slingers is to make them (5) 5/5, better than normal archers (but still weaker then Elven archers). The LOS range weakens them, but they get +0.25 damage on average than archers. IMO, its a good balancing feature. Flavor wise, you take longer to shoot than to fire a stone, don't you?
Also, can I use your army as inspiration for some changes to my units in the "Barbarian Army"?
On the point regarding too much green health, I disagree. IMHO, a "upper level" barbarian unit should have 5-2-5 or so health. Let me explain. They're not as disciplined, given, but they're hard to wear down due to their thirst for war. The low yellow health...well, no reason, technically. The high red health is due to the tendency for barbarians to make "last stands". In my army, there's an ability called "vengeful", which most of the units have. This ability allows them to negate the penalties for being in the yellow/red, which in flavor, means they're trying to get vengeance for their fallen comrades.
EDIT: After thinking about it, the upper level unit should be 4-4-4 or something instead. Or maybe 3-4-5. They'll "last stand" for a long time, making them difficult to wear down. And they just love being in the red for the c+2.
Though....Maybe 4-3-5. Ok...5-2-5...wait... pah just go with what you want...
Ok, maybe I've spammed enough.
