Pikes doing low damage? Are you nuts? Maybe Mordor pikes and Rohan Farmhands, but Gondor, Isengard and especially Dwarf pikes rip cavalry to shreds, especially once they have upgrades. Rohirrim of the Eastfold can put up a decent fight, but without the incredible leaderships provided by Rohans heroes they wouldn't be able to win.
Gondor Knights do not beat Royal guards 1v1, only Knights of Dol Amroth can do that.
Imrahils Leaderships only apply to units of Dol Amroth and the fiefdoms, so they do not effect normal Gondor Knights, they only get the +25% damage buff provided by the Dol Amroth Knights and Faramirs leadership, and Aragorn can give fearlessness once he reaches level 10. Now lets list the leaderships and positive effects that Rohan cavalry gets, to compliment the already frightening size of their cavalry force:
Rohirrim of the Eastfold have a default formation which makes them immune to crush revenge damage, and gives +30% damage and +15% armor.
Théoden gives +25% damage and armor and fearlessness.
All the Captains of Rohan from the Assembly Point give fearlessness.
Gamlings Peasant Summon gives +20% damage and armor.
Gamling can heal each battalion of 1 unit once he gets level 7.
Hama has a constant passive heal out of combat for all nearby allies.
Elfhelm has a fast recharging heal ability.
Eomer gives resources for kills to nearby rohirrim, Memorial at level 7 gives +20% damage while debuffing enemies.
Now do you see what I mean about Rohan's leaderships? Add all of this to the cheap cost in resources and CP, and the Breeding Horses spellbook power, and you end up with an absolutely insane force that can be quickly assembled, and kill any other cavalry force and kill pretty much anything except elite pikes. They are fine as they are, they do not need a buff.
Rohan's infantry can't stand up to Gondor's infantry huh? I wonder why it is that my peasant spam always beats Gondor then, hmmm....
I have used Gondor knights plenty of times myself, and I know for a fact they do not trample as good as Rohirrim, and pikes kill them just as fast as Rohirrim, in fact faster. Rohirrim of the Eastfold slaughter pikes if you use them intelligently. Tower Guards and fully upgraded Isengard pikes excluded for obvious reasons of course.
You are right about the armory upgrade on the tents not working, I tested it out. That belongs in the bug reports however, not here. Good job for finding it though
The topics for more elite and heroic units are all over the place, and do not need to be brought up again here, go to the appropriate thread.