I had an odd problem with cron.
I made three perl scripts: LWP4.pl, LWP5.pl and LWP6.pl
During testing, I put the following entry in cron:
33   *   *   *   *   *   LWP4.pl; LWP5.pl; LWP6.pl;
When it ran, I got 6 versions of each of these scripts running

concurrently and in order also.

They didn't start at exact same time, but as if LWP4.pl, then another

and another, etc.
When first version of LWP4.pl finished, then first version of LWP5.pl etc.
These scripts get a web page, extract values from matches, update

database, sleep, repeat for new pages until done with list of search values.
Chris Bennettf