I would disagree: It actually can increase the likelihood of finding issues, because it causes several batches of thread contention to occur instead of just one, possibly with slightly differing timing between threads (i.e. not all starting at exactly the same time), which can highlight issues which might not be seen with just a single, start-coordinated run.

Still, in this particular case, since it's a pretty easy-to-trigger bug, I suppose we can probably get by with a bit fewer..  Dropping it too low starts risking that the test might be reliable now but will stop being reliable as newer and faster machines come out, though..