1914 AI and MGs

[Nitram Draw]

Are the MG units connected to a specific infantry unit for AI movement orders?
What I see, particularly on the Allied side, is an infantry and MG unit are in a hex. The infantry gets broken and retreats but the MG unit remains in the hex and no new infantry unit moves in, even if there are plenty available. It is then easy to overrun the MG unit.
Another thing I've noticed is the AI tends to stack MG and Artillery units together and the infantry units together.I've seen 3-4 MG units and 3-4 artillery units in the same hex and 2-3 infantry units in the hex right next to it. Now that might not be bad in rear areas but not on the front lines!