A sysadmin is lower than a superuser is terms of access allowed on the appliance. A sysadmin user can perform all Citrix ADC operations with the following exceptions: no access to the Citrix ADC shell, cannot perform user configurations, cannot perform partition configurations, and some other configurations as stated in the sysadmin command policy https://docs.citrix.com/en-us/citrix-adc/current-release/system/authentication-and-authorization-for-system-user/user-usergroups-command-policies.html