Everyone knows too much armour in the desert is bad, I've read that a unit with armour 5 or higher (not including shield bonus) tires at a faster rate in the desert, but I've also read in posts people not giving any armour upgrades at all to any units for use in the desert. Presumabley any armour increase makes the unit tire quicker than it would have done.
Heres what I do, I would like to here other opinions / comments:

Any unit with armour less than 3 gets upgrades to give it a total armour of 3,
eg archers, ghazis get +2; gallowglasses get +1 etc
Any unit with armour 3 or 4 I leave alone with no upgrade, I tend to use less armour level 4 units.
All mounted missile units get no upgrades as I tend to make them do a lot of work running around in a battle and keep them away from missile duels.
I almost never use units of armour 5 or higher in the desert.

I've never really had much problems with fatigue, but I'm keen to learn from the experiences of others.

So comments generally please, also in particular
-Do you leave your guys totally unarmoured?
-Would you use armour level 4 rather than 3 as a base?
-Do you add armour to your mounted missiles (and does that change how you use them)?
-Do you use heavily armoured troops and make a quick assault?