OK, to get the highest MVP award, is pretty straight forward as well. First you play PvP, assuming you have a pretty good team, battle someone. After the match, one of your troops will get the MVP award. Do this 3 times, and the achievement is yours.
I unlocked it fairly quickly. Not too sure if it has to be 1 troop, or any troop. I know that I had to play 4 matches to get this, so its probably one single troop that has to land the MVP.
Good luck, and have fun!