1 jobcard = 1 JCL - I presume you mean you have created 4 jobs in one member of a PDS.
Waht do you mean by 'JCL compile' - do you compile ACF2 rules? I do not know. You compile program source (usually) and you can do that in background, using JCL, or foreground using the ISPF panels.
Can you process more than one id at a time - what does the manual say, or, if you cannot be bothered with reading it why not try with just 2 IDs to start with and if that works then run again with the remaining 41 IDs.
The problem I have is that people can explain things quickly but I can only comprehend slowly.