Product : NetApp, NetApp HCI [HCI]/1.6, x86
Feature : Mixing Allowed, Server/Node, Server Support
Content Owner:  Herman Rutten
Summary
Yes
Details
Compute and storage nodes can be mixed and matched as long as best practices are adhered to.

NetApp HCI allows any storage node type to be mixed within a single cluster, however one important rule is mandatory: no one storage node can be more than one-third of the total cluster capacity.