RE: AI Movement Points
As Mr. Grumpy noted, the step from C quality and above to D quality and below causes units to move slower as they can no longer move 4 Clear hexes each turn.
Units also have a Speed rating, so even if a unit look like it's the same type as one of your own and the quality is identical it can move at a different pace. For FWWC games that's the case with many Jaeger units for example, as they have Speed 5 whilst other infantry units have Speed 4. Motorized Jaeger units use the Deployed movement rate when not in Travel mode so they have Speed 4.