Datapumping OJVMSYS schema

I've got a 12.1 SE2 database on Solaris where the USERS tablespace is now quite fragmented following archiving and removing of application data. I was thinking of rebuilding it, and reducing the number of files by creating data files of a larger size. 

The plan was to get a list of all the schemas that had segments in the USERS tablespace, performing a datapump export of schemas before dropping them. Then create a temporary NEWUSER tablespace to switch any accounts whose default tablespace was USERS and change the system-wide default tablespace to the new tablespace. Then I could drop and recreate USERS and reload the dump, and reverse the default tablespace for the system-wide and users from NEWUSER to USERS before dropping NEWUSER.