Product : Citrix, Citrix Hypervisor/8, Standard
Feature : Cluster Size, HA/DR, VM Mobility and HA
Content Owner:  Roman Macek
Summary
64 hosts / resource pool
Details
64 Hosts per Resource Pool.
Please see Citrix Hypervisor Configuration Limits document https://tinyurl.com/y5o67fdj
Note: the maximum pool size, for Express edition is now restricted to 3 Hosts.