cron does not care how many scripts, same or not, you are running. It will just start the task at scheduled time.
So if you are good with running a script second time while the first one is running, there is no problem.
Although it depends on the script but usually unless necessary most of time it might create unusual results due to race conditions created by running multiple instances of the same script simultaneously. To avoid that there are multiple mechanisms that ensure that only one instance of a script is running.
The main point is, if you are good with it,
cron won't complain.