TERR service installation should have a dedicated node manager
"Important:
Do not install the TERR service on a node that contains other services."
https://docs.tibco.com/pub/terrsrv/1.3.0/doc/html/GUID-6276FE84-FB9F-4FE7-9EAF-A4CF80F34359.html
Seems best if the Statistica Service has the same requirement.