Best boosted with a partner on the Tomb Robber level. No need for minions, simply run right at the junction from your starting area and smash the vases in the corner, netting a small amount of gold. The other person then quits out, awarding you the win. This takes mere seconds for each attempt and the longest you'll have to wait is in the actual lobby at the start of every game.
It is worth noting, however, that it is best to do 25 of your 50 Pillage matches in Grab the Maidens if you have the DLC, this way you'll get the achievement for 25 wins in an expansion map, saving you doing 25 over and above the 50 required here. Grab the Maidens is a collossal pain, but once you hit a groove, you'll be fine.