Tuidjy usually gives good advice - listen to the Laird of La La Land.
Don't play Ulm.
If you do : forget a lot of what you've been told. First: Unless it's been changed recently, it hasn't seemed that troops incur fatigue while walking, even if they really
should. Infantry walks across the field with no fatigue; armored light bows takes five turns to start getting tired...
Logically, troops _should_ get tired wearing heavy armor, even just walking. Near as I can tell, they don't - that's why archers never get tired, and why heavy infantry doesn't fall asleep even in the rear of the battle formation.