Brainstorming, as I'm sure some of these are harder to code than others:
Bonus in X terrain (Easier movement and combat bonuses), lighter or heavier cavalry (Speed and attack or defense change), unit upkeep changes, ability to build improvements of type Y near the city, -X% cost for buildings or units rounded so it doesn't affect cheap units. The ability to build packs of certain units (Such as building a pair of Starcraft zerglings at one go.) Perhaps the ability to take multiple city actions per turn, with debuff Z for units built in this time and destroying free population or more resources.
More importantly, it was also act as a test of character; given your honesty, it should suffice to say that I do not believe I will have to PM any of my turns from here onwards.
Please, accept my apologies, I am paranoid like that when it comes to war games.
I'd be worried if that was your only such test, as then first would have just proven me an idiot for being so obvious about having changed my turn. I fully expect another test, with you moving first, where I wouldn't be leaving obvious edits lying around. Of course, this is problematic as I'm now expecting it, and so I (if I
was the sort to base a turn off of yours) wouldn't do something that would otherwise be a stupid move, save for the knowledge of your action.
Also, assuming your action had been legit, my lone spearman unit would have had a mere ~25% chance of victory. (50% from initiative and getting a nearly unwinnable 2v1 battle, 50% from a 1vs1 battle.)
Go ahead, be paranoid. I don't much mind losing due to being psychologically or diplomatically outmaneuvered in games. It's part of the fun, so long as it's constrained to the game.