If you mean the CL did this:
PGM
Call step1
Call step2
Call step3
ENDPGM
Then yes, it's a single job and step2 will not start until step1 ends. I
don't care if it starts from w/in a single-threaded jobq or from w/in
QUSRNOMAX. :)
The only way I can see a single-threaded jobq being important would be
if the cl was:
PGM
SBMJOB job(step1) cmd(call step1)
SBMJOB job(step2) cmd(call step2)
SBMJOB job(step3) cmd(call step3)
ENDPGM
In that case you'll need a single-threaded jobq.
-Walden