The fastest way to win matches is doing this in Skirmish, Deathmatch, no Fog of War, and the AFTER PARTY Skull.
Don't do this with Strongholds! The enemy just spams units and it's annoying... and takes longer.
After Party Skull gives you a free tank and infantry every time you lose a base.
Pick Pavium, Deathmatch, 9999 resources, an Easy enemy AI(UNSC), Sentry map(I like the base spawns), and the Skull AFTER PARTY.
Any other helpful Skulls, and NO Fog of War.
When the match starts, quickly build on all the build points around the map, then on the closest 2 mini-base build points to the enemy base, build then instantly destroy the building mini-base. Go to the other mini-base, build, instantly destroy. There's a 4 second timer between rebuilding, so just switch between them and you'll have max pop in almost no time! Then select all units and target the enemy base!
If you need any reinforcements, just destroy some more bases. After you have max, population and sent your units to attack, you might as well just go around upgrading researches, building buildings everywhere, to get more leader points and activate some offensive powers to make it go faster.
My first match doing this took 4 and 1/2 minutes. It can probably be done much faster.
Repeat 3 times for the achievement... or however many are left.
Enjoy!