Improve JCL for EQQPMCKP member of SEQQSAMP (Checkpoint merge)

The current JCL is difficult to understand and modifying this JCL incorrectly may result in a controller that cannot start up .

This is the current JCL from SEQQSAMP member EQQPMCKP after running EQQJOBS: 
 

//COPYCKPT EXEC PGM=IDCAMS,REGION=0M

//SYSPRINT DD SYSOUT=*

//CKPTOLD DD DISP=SHR,DSN=TWSZ.V9R3M0.CKPT.HCL

//CKPTCUR DD DISP=SHR,DSN=ZWS.MIGTEST.CKPT

//CKPTNEW DD DISP=MOD,DSN=ZWS.MIGTEST.CKPT.NEW

//SYSIN DD *

REPRO IFILE(CKPTCUR) OFILE(CKPTNEW) COUNT(1)

REPRO IFILE(CKPTOLD) OFILE(CKPTNEW) SKIP(1)

/*

nothing tells the customer that CKPTNEW must be allocated before running this job,

and after running it,  CKPTCUR must be renamed and then CKPTNEW must be renamed to the name that CKPTCUR had

This is my suggestion for improving the JCL so that no extra handling steps are needed: 

//DELETE EXEC PGM=IEFBR14

//CKPSAVE DD DSN=ZWS.MIGTEST.CKPT.OLD,

// UNIT=SYSDA,SPACE=(TRK,0),DISP=(MOD,DELETE)

//ALLOCNEW EXEC PGM=IEBGENER

//SYSPRINT DD SYSOUT=*

//SYSUT1 DD DUMMY,DCB=(RECFM=F,BLKSIZE=256)

//SYSUT2 DD DSN=ZWS.MIGTEST.CKPT.NEW,

// DCB=(RECFM=U,BLKSIZE=8200,DSORG=PS),UNIT=SYSDA,

// SPACE=(CYL,1,,CONTIG),DISP=(NEW,CATLG)

//SYSIN DD DUMMY

//COPYCKPT EXEC PGM=IDCAMS,REGION=0M

//SYSPRINT DD SYSOUT=*

//CKPTOLD DD DISP=SHR,DSN=TWSZ.V9R3M0.CKPT.HCL

//CKPTCUR DD DISP=SHR,DSN=ZWS.MIGTEST.CKPT

//CKPTNEW DD DISP=MOD,DSN=ZWS.MIGTEST.CKPT.NEW

//SYSIN DD *

REPRO IFILE(CKPTCUR) OFILE(CKPTNEW) COUNT(1)

REPRO IFILE(CKPTOLD) OFILE(CKPTNEW) SKIP(1)

/*

//RENCKPT EXEC PGM=IDCAMS,REGION=6M

//SYSPRINT DD SYSOUT=*

//SYSIN DD *

ALTER -

ZWS.MIGTEST.CKPT -

NEWNAME(ZWS.MIGTEST.CKPT.OLD)

ALTER -

ZWS.MIGTEST.CKPT.NEW -

NEWNAME(ZWS.MIGTEST.CKPT)