This information is to address general questions about Nintex Services in SharePoint 2016 pertaining to MinRole and where they should be running.
Nintex External Services installed on all the servers in the farm, But default to run on server with Central Administration. User can configured to run these service on any server in the farm, but should only have 1 instance running per farm.
These services are MinRole compliance to run for server with Role
Web Front End
Service here refer to SharePoint windows services with AutoProvision on MinRole as follow:-
Nintex Connector Workflow Queue Service
Nintex Workflow Start Service
Nintex External Relay Service
The following service is just SharePoint Service and it not designed with AutoProvision