Hello!
A vPC domain must be configured between two Nexus switches of identical models. Since the N9K-C93180YC-EX and N9K-C93180YC-FX are two different models of Nexus 9000 switch, a vPC domain between these two models would not be supported.
As a side note, this same logic applies to line cards inserted in end-of-row Nexus 9500 switches. The vPC Peer-Link must be configured on the same model of line card on both Nexus switches.
For example, if you have two Nexus 9508 switches with N9K-X97160YC-EX line cards inserted in slot 1, you can configure the vPC Peer-Link between both line cards. However, if you have two Nexus 9508 switches where one has an N9K-X97160YC-EX line card inserted in slot 1 and the other has an N9K-X9736C-FX line card inserted in slot 1, you cannot form the vPC Peer-Link between these two line cards.
I hope this helps - thank you!
-Christopher
