Quoting ScottTykoski,

reply 1

That is all by design - we've updated the description for the next update

Your kidding, i hope. For if so then: Out with the 'Band of the Vanguard', and in with an additional 'Ring of Extreme Haste' and 'Tireless March' on a different unit. Let me explain what i mean.

• Casting 'Tireless March' on a single unit in the army will free up a slot (that would normally be taken by a 'Band of the Vanguard') for every unit in the army.
• The larger the army, the more units can have 'Tireless March', and this would mean more movement for this army. And more movement almost linear translates in more battles for the given army per turn. And more battles mean more XP gained. More XP faster means more powerful units earlier in the game.

I am afraid if this is as intended then the game that supplies the player with 'Tireless March' early in game might as well have a SK dialog popup show which would state: "You have Tireless March, therefor i am going to kill myself now. I'll just nip off and shoot myself. Don't worry, sir, I'll be very humane". (quote from the main dish in 'The Restaurant at the End of the Universe')

Quoting ScottTykoski,

reply 3

So lets say you have a 'Doom Stack' of 7 awesome guys. For the horrible maintenance fee of -7 Mana per turn you can raise that stack's speed by 1...I don't see how this is a game-breaking issue  

If it stacks wouldn't that be +7 movement for the whole army, or am I reading the OP wrong?

From my testing, there is no Stacking going on with 'Tireless March'. You can't cast it twice on the same unit, and it doesn't give a flat bonus to the army moves that stacks.

SK uses the same system as LH to average out the total moves of a stack. So even though one guy has mega moves, you put him with slower dudes and he's going to get slower too.  So, in order to exploit movement spells & items you've going to pay the price in army size - and I'm totally cool with that! A great way to give the player choices with tangible consequences.

Hope this clears things up  

CW: Can you send me that save file to scott@stardock.com?  I want to investigate with the newest code...I can't get this one to repro on my own.