I think the documentation needs some woork :-)
Forget the COBOL first, and get to understand what the link-edit/binder does. REUS is used to determine whether an existing module in memory can be used to service a new "call/load" outside of the current run-unit.
For batch programs, that's not going to mean much directly unless there are multi-threaded batch applications.
If you use REUS=RENT then COBOL CANCEL won't work. However, if the program is truly re-enterable, that won't matter - and who uses COBOL CANCEL anyway.
The only link between how a COBOL program is compiled and linked/bindered is "manual". In batch programs I can't see that it matters which linkedit/binder option you use. For "online" programs you need to do as you are told, to avoid chaos.
BillWoodger