I've not read the whole thread, and not seen any precise set of rules.
What's stopping us from designating some of our ridiculous horde of troops to, AFTER THE BATTLES, recover a few master-archer arrows? And, while we're at it, a few master archer bows, some enemy armor, and anything left of any dead enemy mages?
And we should probably figure out some way to get our mages more active. From what I've read, it seems like we call lightning a lot less than the enemy shoots fireballs. Just start it raining. 10,000,000-ish volts. Oh, and why can the "Hammer" only be used one half of the year???
(Actually I think lightning happens between 10 and 120 million volts (Yes, that's the closest modern science can get. Differing conditions generate lightning at different voltages), and skyrockets air temps to somewhere over that of the surface of the Sun. Survivable, since the amperage is often just low enough....but you're likely never going to fight again, and will certainly be unconscious for quite a while. Heck, might be that nobody can even survive due to rudimentary medicine, compared to modern standards)
Somewhere here, we need to start a school of Glass Cannon-ing, where you educate a bunch of farm yokels in how to blow the enemies up, not blow themselves up, and, MOST IMPORTANTLY, not hit any friendlies, since we don't actually care about them.
Heck, just have these guys carry a shield with no other armor, sprint into the enemy lines, and start casting varieties of the targeted and untargeted lightning strikes. Medieval suicide bombers! If they make it close enough to fry enemies when they die, it works great! If they manage to fry enemy mages and commanders BEFORE incinerating themselves, it works even better!