@End_of_Eternity - Except your second solution is not possible. If you look at your 3,2 it is not possible for a pink to be there as that breaks the order of blue - pink - blue along the 2nd row, by causing it to be pink - blue - blue
As far as speed scaling goes, from what I can see it works like thus: Your Speed / Enemy Speed = No. of your attacks per enemy attacks. E.g.: If you have 500 speed and the enemy has 250, you will get 2 attacks per each enemy attack.
@TaoDragon - As far as I can see, for corner matches at least, there is a reward, but it is not stated obviously. You will get double the amount of mana from a corner match as you would normally (A corner match of 5 will infact give you 10 mana instead of just 5)
@GrandmasterSage: Stuff like that happened in the previous versions too. There's a random chance when placing a unit that it will get a 2x damage bonus or something like that, not exactly sure what it is, but there's a chance it will be more powerful than normal.