I would generally like to see Isengard get a small debuff. I think heavy armor is a little too heavy. Isengard is extremely powerful once you can camp your upgraded crossbowmen behind fully upgraded Uruks.
Since this is not a balance related topic, you should post this in a different thread. Same goes for your suggestion concerning spear throwing elves. ;)
1) summoned cav battalions from 15 to 10 men eachI also suggested that a few times, so it also sounds good to me (Quick reminder: My alternate suggestion was to summon one battalion on horses and one as swordsmen)
2) summoned wildmen’s bonus damage vs building from 50% to 30%Sounds reasonable to me.(+maybe changed damage type)
3) Uruk’s cost from 300, 400, 400 to 400, 500, 500I do think that my suggestion (mineshafts = faster recruitment speed for Uruk Hai instead of lower costs) adresses the problem much better. Your suggestion would raise Uruk Hai costs but also raise the total discount per battalion given by mineshafts while also making the Uruk Hai stronger. I think their strength right now is pretty fine and to just take away the cost reduction would nerf them really well.
4) More hp and damage for uruks (if they now have 15% more than Gondorsoldiers I could imagine giving them 30% more than Gondorsoldiers)
Making the wildmen better against units is exactly what caused the problems in the past where you just throw all summons against the enemy army and annihilate it. If anything, their damage to units should go down even further to differentiate the different summons.Yes, that makes sense, I guess. My idea to change the damage type was only meant in case they would be to weak otherwise, but I agree with what you said.