Thank you for your extensive reply! You actually read my mind because I will add undead at some point. They will have spooky skeletons that reassemble after getting destroyed, and zombies that bite enemies and turn them into more zombies. Humans will probably follow up aswell but I have not decided a theme for their army yet. I thought of using the right click button on pc, but I'm not sure how to implement it when a character can both shoot, attack in melee or use an ability on an enemy. Do I default to shooting when both attacks are available? Also my end goal is to have the game ported on a tablet, so you can pass it to your friend after you concluded your turn, so no right clicks there. The same problem, as you pointed out, happens when switching characters. In the next update I'll make it so it automatically selects the other character if it's the only option available when clicked, instead of bringing up the menu every time.
As for balance problems, it will require some drastic changes. As you pointed out, spamming low cost units is the best strategy (for every race, not just orcs). I thought I could balance it by adding more abilities (and, in turn, versatility) to high cost units, but that has not been enough (expecially against the AI which, at the moment, isn't smart enough to use skills yet.)
Again, thank you a lot for your input! I hope you had fun!