Limit of async jobs?

I've read different posts about concurrent sessions and threads and round robin, etc.  I'm still not clear how many async update calls I can throw at NetSuite at a time.

For example, let's say my fulfillment monkey is crankin' away fast as ever and he's clearing a job every 5 seconds (possible, he's fast) if I were to initiate an async update every 5 seconds and they were overlapping (n+1 starts before n has finished) am I going to run into trouble?  Is this the point of the async methods, to allow this functionality?

Thanks for any suggestions,
Steve