UNSC vs Mekanoids (A FUBAR batrep)

Since I couldn't go to work yet (waiting on paperwork with the company) I decided to play a game with the kids (school hasn't started yet).  I let them pick and they wanted to play with the 15mm figures, so FUBAR it was.  They wanted to use the AT-43 walkers I've appropriated (and still need to repaint) for the Mekanoids, so I grabbed those and the handful of Grenadiers I have. I only have one vehicle for the UNSC, a grav tank, so I tweaked the spider drones to have some small laser anti-tank guns and gave myself a squad of 8 infantry and a support section with two LMGs.

Here is the initial set up:

The scenario was that the Mekanoids were advancing on the flank of a larger battle. The UNSC had hastily gathered a reaction force to block the advance of the 'bots.  The objective for both sides was to remove half of the opposing models, forcing them to retreat.  The first turn involved some maneuvering and only one shot which had no effect. (In my mashed up version of FUBAR weapons can fire up to twice their listed range at 1/2 firepower dice.)

End of 1st turn:

Turn 2 was more movement then Alexander opened up and destroyed my section of anti-tank drones before they could even get a chance to fire. The grav tank immobilized the rearmost of Alexander's walkers with a shot that threaded a needle between the buildings:

In turn 3 my grav tank got into position and eliminated Phil's walker in one mighty blow as well as taking out one of his grenadiers. Alexander tried in vain to take out the infantry on the bridge.

Turn 4: the grav tank turned to engage the walker threatening the infantry and takes out the flamethrower. The infantry throw grenades and immobilize the walker while the fire support team takes out two of Alexander's grenadiers.

Turn 5 and end game: The support team took out enough of the remaining grenadiers to force a retreat by the 'bots before they got a chance to engage.

Some thoughts on the game:
1) I still need some practice on balancing forces without a point system.
2) I need to sit down and finish the point system I've written some notes about
3) Either I'm not handling infantry armor saves correctly or I need to change the mechanic. That walker should have put a hurt on the infantry.
4) The tank didn't get a scratch on it, though I think was due more to keeping terrain between it and the opposing vehicles, not a complete test of it's stats. In this game though it seemed maybe a bit overpowering.
5) The next game will be over more open terrain so vehicles can strut their stuff.
6) Mobility to use terrain to screen models is key.