Yes, compatibility, absolutely.
Just considering the 7321.
It is EOL. Final firmware is 9.12.3 MR3, might not be an issue presently but you cannot upgrade ZD beyond that firmware without losing all the 7321's you have in your config, they will not work!
ZD latest firmware is 10 so you are already potentially missing features/fixes that might or might not be applicable/desirable for you. You will fall further behind the latest firmware path over time.
Edit:Just checked 7352, 7372 are supported in ZD f/w 10. So 7321 will be your Achilles heel.
Your choice now could easily haunt you in a year or two so think hard about buying old kit.