I concur with rstech, cut them from from one database, paste to another works fine offline.
If you copy/paste (instead of cut/paste) the compiler will still attach to the Program-scoped tags, which is not what you want.
I recommend you do not have Program-scoped and Controller-scoped tags of the same name, it will just cause confusion to anyone looking at the code later.
Of course you can have same-named tags in multiple program tag databases, and that is a bonus if developing code for multiple machines, or machines with multiple lines/lanes/cells etc.
I do recall that in the very early revisions (6'ish) the compiler would choose to attach to a Controller-Scoped tag of the same name as a Program-Scoped tag, but that was fixed long ago....