ACTGRP(*CALLER) vs. ACTGRP(*NEW) for CRTBNDCBL

List,

I've just discovered a dilemma for which I need advice. I have custom 
compile CL setup for us to use from WDSC - one for CBLLE and one for 
SQLCBLLE. While testing a program that successfully compiled, I encountered 
some strange run-time issues that I traced back to the fact that a 
subsequent CALL of the program (executing it from the green-screen command 
line) would have program storage set the way it was left on the previous 
instance instead of being initialized.

It was recommended to me to use ACTGRP(*CALLER) when I set up this CL. I 
think that using ACTGRP(*NEW) would solve the problem I encountered earlier, 
but here's the issue. We have programs that are "main" programs and we have 
those that are called "sub-routines". All of them will be bound COBOL. 
ACTGRP(*CALLER) would be correct for the sub-routines (since most of them 
will be called numerous times from a main program) while ACTGRP(*NEW) would 
be correct for the "main" programs.

There is no easy way to determine (from the program name or type) which it 
is - main or sub-routine. So how do I handle this?

Do I need one compile CL for a "main" program (with ACTGRP(*NEW)) and a 
second for sub-routine (with ACTGRP(*CALLER))? Or, is there a third setting 
that would correctly satisfy both?

If so, how can I ensure/enforce that the programmers use the correct CL when 
they compile? This is not the kind of error that will surface right away.

It could be that the solution to this is simple and straightforward but I 
don't see it (being new to the iSeries world). Your suggestions and advice 
will be greatly appreciated!