There is no stock way to do it in SMF, mostly because the sort of thing you're trying to do is pretty discouraged as users can reorder the board listing at their leisure.
However if you wanted to guarantee the order worked the way you wanted it, you could edit the smf_topics table and change the is_sticky values. As long as they're all > 0 it should function the same and order them highest number to lowest, so if you have 5 topics, the first one should be 5, the second 4 until you get to the fifth topic being 1.
It might get hairy if ever unstickied and stickied again but can't prevent that sort of shenanigan without code change.