So, they made a coordinated attack while the Commandos were landing behind the enemy's lines? This needs a lot of coordination between the players.
1. You get close to the line hit SMOKE RAID (60 munis). Smoke floods the area.
2. Hit ASSAULT to make your units push better (optional but 90 Munis).
3. Throw grenades on the MGs.
This strat works early-mid game since it requires 3 CPs to unlock the smoke raid.
One of the statistics guys can affirm, but the ASSUALT adds a little sprint to get you past the MGs etc. It may have been nerfed this patch to move slower.
Last patch, the inf could sprint right thru the MGs if timed right. No need for smoke at all. It was bat-shit OP. Which brings up the issue I have with commanders. Picking the right commander should not drastically change the game.
But generically it seems the pros say:
BRITS - Smoke, Grenades, Mortar pit.
USF - Mortar Smoke, grenades, mortar half tracks.
SOV - Smoke, 120mm mortar, Con sprint w/ppsh or shocks to get close and deal damage.
SKIP MY RAMBLING
I think the thing that trips everyone up is that things are meant to counter at certain times in this game. Each thing allows you some domination time. Along the order of 1-4 minutes. Where everyone thinks they made X, I need to counter with Y. And if Y does not quickly counter, then the game is busted or imbalanced. You did not anticipate unit X so you lose territory for a certain time period.
That is how I feel about bunkers, bofors, etc. They are not meant to win the game. Just buy you time in the VP race.