[Greybeard]

It seems to me that it would be appropriate for the game host to contact players who are habitually late and ask them if they could submit earlier. Perhaps they have a real life situation that keeps them from submitting earlier, but they may just be procrastinators %^).
If it's explained the them that usually they are delaying the turn by about "x" hours after the next to Last submitter, they may be willing to "try harder" and submit earlier. It would certainly be worth a try...Greybeard