That's the biggest problem with DMR radios, at least those I know of, that they all use a common user id and TG list for the whole radio. When the same TG number are used in different systems I usually nametag it generally as TG5 or similar without any special service named.
I know there have been requests in the forums for MD380 to develop TGs that can be selected to only be used with a certain system but it is probably way too complicated to code.
/Ubbe