Australian standards dictate that courses should be set for Australia's best runners, not world best. Given Henry is arguably one of Australia's best, this is the standard that should be set to.
I recall when Jen used to run all the NavDash events she'd set it to a winning time for whoever was likely to be there on the day, so when Lucky Luke was in town the courses would be longer than usual and were generally well within the winning times.
Now having said all this, hopefully the event I'm setting gets within that time!
One of the problems with our sprint events is that a lot of members and quite a few newbies don't want to enter into the spirit of 'Sprint O' and therefore they do the Long course (to 'get their money's worth') and they take a long time, up to an hour. For that reason I would set the length at 12 minutes for Henry, not 15 minutes.