My 2v2 partner and I are Terran/Zerg and in high bronze, working on our fundamentals to get into silver/gold. When playing a walled off (shared base) Protoss and Protoss or Protoss and Terran we've started developing a push of 5-10 marauders with concussive shells and 20 or so speedlings. We go into push mode if we scout and they are not rushing.
We rally close to the enemy base, and then I head in first with marauders focusing my firepower on the weakest point in the wall. Once the wall is busted, he rushes in with his zerglings and tries to do economic damage. It's a little like a baneling bust. In bronze this has started to work really well. If we don't roll over them, we usually do enough damage that successive waves of attacks eventually win the game.
I haven't seen the marauder/ling as a recommended team combo. Should we be continuing to work on this build? Will this be effective in silver? What counters should we look out for?