FWIW:
Here is the SP start for the last few medalists:
2017: Chen (last group; 3rd in 2016); Zhou (second to last group) and Brown (last group; he did not have a bye since he was not at 2016 nationals, but Jason seems to get this draw)
2016: Rippon (last group; 2nd in 2015); Aaron (last group; 4th in 2015) and Chen (1st group)
2015: Brown (second to last group; 2nd in 2014); Rippon (2nd group) Farris (last group, 4th in 2014)
2014: Abbott (last group 3rd in 2013); Brown (2nd group); Aaron (last group, 1st in 2013))
2013: Aaron (1st group); Miner (last group; 3rd in 2012); Abbott (last group, 1st in 2012)
Being a past medalist (or consistently in the top 5) helps in getting a later start number, but with the exception of last year, there is at least one medalist who isn't in the last two groups in the SP and there hasn't been a year where all three medalists were in the last group -- so if the top three is Nathan, Adam, Jason, it would be a new pattern, LOL.
(yes, yes I know pewter, but since top 3 will likely get selected for Olympic team, focusing on those placements for this exercise). And of course correlation =/= causation.