Investigate robustness of determine_queue.cwl

[thomasyu888]

If there are concurrent submissions running on the main queue, the determine queue doesn't seem to do a good job of fanning out submissions.

It doesn't seem to be an issue if you just run one submission at a time on the main queue, but theres a minute overhead per submission...

[vpchung]

I've tested with multiple concurrent submissions throughout the day and it seems to be working fine, though I do notice a bias for Internal Queues 1 and 2.

Will continue testing to know for sure.