The higher the number is not the higher priority. It's just so the scripts are run in an order - you can add scripts to the directory. It doesn't matter what number you give it - as long as you watch out that you aren't starting something first that needed another service. If you aren't sure, add it to /etc/rc3.d/.

You could name them S01aaaa, S01aaab, S02aaaa and they would run in this order:
S01aaaa
S01aaab
S02aaaa

Since you want to be descriptive, you set up the names to give a clue of what you are doing
S88sendmail
S73named
S92volmgt
S75cron

You would see the order if you did ls -1 S* on the rcX.d directories.