The modeling is perfect! no comments there!!!

However, and this is just a minor issue offcourse, the gatlings will always be pointed in the same direction as the big guns.
Due to their placement their rotation circle is very small.

If a target could be taken out by the gatlings, you wouldnt need the big guns, and if a target was to be taken out by the big guns, chances are the gatlings are not very effective against it.

A little suggestion, please take no offence, replace the gatlings with missile racks, and mount the gatlings underneath the torso on a turret.

That way the gatlings can sweep out the lighter units in front of the mech, while the big guns are aimed at that enemy armor, with missiles ready if it should prove insufficient.