Excuse me? My advice was helpful, you have to accept the fact that the paladin wears armour all the time. Yours was downright silly. Make the fights easier? Why? So the wizard can tank and it can be a cakewalk? Yeah, thats... great. You'd be better off removing the fights all together.
"I want to do X. How can I do it best."
"Don't do X."
For some values of X, your approach might be a good idea. (Say, X = Suicide, Buying Britney Spears Albums)
A crippled wizard in a wheelchair who has never left the library is more agile and better able to deal with avoiding blows than a battle hardened paladin without armour. DO NOT REMOVE THE ARMOUR FROM THE PALADIN. The system DOES NOT SUPPORT IT. It makes more sense to let the paladin sneak in the armour than it does to watch the crippled wheel-chair bound wizard be the tank. He's just so good with that armour he doesn't even make a sound.
The Paladin is still the better tank, since he has loads of hit points and healing surges, and is able to mark his foes.
As for the paladin's motives: He's in a fort that is generally run by "good" people. He should have enough social grace and nobility to know how to get around right?
Well, I think he should, whether he does - you'll see.
I'm wondering why the D&D 4e system is unable to handle this type of adventure. Supposedly the math is "perfect" right?
The math is "perfect" if you use the basic assumptions of the system. One part of is that some classes use armor, not their own reflexes or cunning to rely on their AC. And to some degree, every class needs its armor - the Wizard will be wearing magical clothing that increases his AC.
If you want to remove the armor on a general basis (not just for one scenario), you will have to compensate for it. You might want to give Paladin a "Armor of Faith" ability that is equivalent to a plate armor, or a Fighter the "Tough Armor" ability that is equivalent to scale mail. If you want to remove magical items, you need something to replace the +1 to +6 to AC/Defenses/Attacks/Damage and the +1d6 to +d6 to critical hits.
The nicety of the system is that the assumptions on bonuses from equipment are very transparent.
I am wondering - if people are not allowed to wear armor, will they allowed to carry weapons (or implements)?