HIPER-V dynamic memory - assigning more maximum memory that phisycal

The physical machine has 16GB of RAM

Can I configure two VM’s with dynamic memory allocation like this?

1. 4GB start; 12GB Maximum; priority low
2. 2GB start; 14GB Maximum; priority high

What about the memory required by the host (~2GB)? Is there a way to "fix" the host memory to ensure that it has the necessary ammount to run properly?

I know this is not necessary a best practice, but I have one machine that - every two hours – performs a highly memory demanding process and then becomes almost idle and the second one, that works constantly, will benefit from the extra memory in the time between.