You can configure instant-clones to reuse existing AD computer account names.
Enable this option if you have a limited number of computer accounts to use. When an instant-clone is created, if an existing AD computer account name matches the instant-clone virtual machine name, Horizon 8 uses the existing computer account after resetting the password. Otherwise, a new computer account is created. When the instant clone is deleted, Horizon 8 does not delete the corresponding computer accounts. The existing computer accounts must be located in the Active Directory container that you specify with the AD container setting.
When this option is disabled, a new AD computer account is created when Horizon 8 creates an instant-clone. When the instant-clone is deleted, Horizon 8 deletes the corresponding computer account. If an existing computer account matches the instant-clone virtual machine name, Horizon 8 reuses the existing computer account after resetting the password.
This option is disabled by default.