Adding armor units to the attacking force makes the rubble lines even more important. The Ogre can go where it wants, but the GEVs have to maneuver around the rubble. This gives the defender a chance to use that pesky rubble to his advantage for a change.
A line of 1/1 INF strategically placed between rubble and craters can buy the defender an extra turn if a GEV makes a break for the command post.
Here's a picture of 6 INF effectively blocking 11 of the 15 columns of the map.
There aren't any overruns in OGRE, so the GEVs have to stop and attack if they want to punch through the line of INF. If the attacker times it right a GEV can end it's first move adjacent to a defending INF, destroy it in the attack phase, and use it's second move phase to get through the line. Even then, any INF adjacent to the "hole" in the line can move 2 and get one attack in before the GEV is in the clear. A double line of 1/1 INF is more effective, but at the cost of tying up more units.
This also gives the INF something to do besides shooting at treads while getting chewed up by AP guns. In fact, if there are no INF in range of the AP, they're useless until they're in range of the CP. Screening the CP with INF, per Heatdeath's post above, may be a way to effectively neutralize one of the Ogre's weapons systems.
I want to play this one some more and see how adding or removing rubble changes the effectiveness of INF. Increasing the number of craters gives the Ogre fewer options, and results in fewer hexes from which the Ogre can be attacked. There are lots of possibilities to explore here.
Neat!