Currently a toollabs user has no influence of the order jobs are executed. Please also set weight_priority so that users intended priority of jobs is respected, too.
My problem was that i submitted two array tasks with hold_jid_ad dependency A[i]->B[i].
All tasks of job A were scheduled before any task of job B started because Job B was submitted 3 seconds after A and so has a lower waiting time priority.
Because A creates large temporary files which B reads and deletes, i prefer runnable B tasks to have a higher priority than not started A task.
There i also many other cases where i prefer influencing job priority a bit.
$ qconf -ssconf
Maybe 0.1 for weight_priority.