Sorry, I should have been more clear. I meant this in regards to first time steeplers in their debut race then comparing it to their best time later that same season. I'll use the names you provided as examples.
O'Hare his freshman year
Debut/First Time: 10:40.81
Best time for that same season: 10:00.05
MIAC: Did not qualify
Time difference between first and best: 40.76 seconds
Rosenau his freshman year
Debut/First Time: 9:57.88
Best Time for that same season: 9:51.00
MIAC: 9:51.00 for 8th
Time difference between first and best: 6.88 seconds
Carston Dammann his freshman year
Debut/First Time: 10:32.54
Best Time for that same season: 10:15.58
MIAC: 10:31.90 for 18th - *We can all agree this was a poor race
Time difference between first and best: 16.96 seconds
Lachlan Hinwood his Sophomore year
Debut/First Time: 10:18.52
Best Time for that same season: 9:48.62
MIAC: 10:10.28 for 14th... also not great showing here
Time difference between first and best: 29.9 seconds
For historical comparisons, here are the last few great MIAC steeplers and their same progression their first seasons.
Ryan Bugler (SJU '17) his freshman year
Debut/First Time: 10:09.44
Best Time for that same season: 9:45.98
MIAC: 9:45.98 for 5th
Time difference between first and best: 33.46 seconds
Best time by graduation: 9:04.84 - national champion and all American
Jake Brown (Olaf '15) his junior year *transferred to Saint Olaf and only ran steeple 7(!!) times in college including prelims
Debut/First Time: 9:44.07
Best Time for that same season: 9:09.49
MIAC: 9:09.49 for 1st *Ran steeple twice this season, qualified for nationals, didn't even go
Time difference between first and best: 34.58 seconds
Best time by graduation: 9:01.43 - 3rd place against one of the most top-heavy steeple fields in a decade at nationals
Marcus Hudurle (Carleton '14) his freshman year
Debut/First Time:9:58.19
Best Time for that same season: 9:34.24
MIAC: 9:41.59 for 5th
Time difference between first and best: 23.95 seconds
Best time by graduation: 9:06.87 - made finals at nationals multiple times
Ryan Peterson (Halmine '16) his junior year
Debut/First Time: 9:34.71
Best Time for that same season: 9:25.05
MIAC: 9:58.99 for 8th *If anyone remembers that race, it was rough for him
Time difference between first and best: 9.66 seconds
Best time by graduation: 9:10.43 - last person out to not qualify for nationals in one of the fastest year of qualifying in the last few decades
Average time improvement for all of the names listed above in first season of steepling from first race to the end of that same season: 24.53 seconds - give or take a tenth of a second.
Average time for mortals (names you listed at the top): 23.63 seconds
So, while there are outliers, the average improvement rate for MIAC runners largely remains the same at about 23-24 seconds for steeplechasers in their very first season of doing the event from their first to last race of that same season. It would be much more difficult to map out all 4 years of progression, of course... Also keep in mind that this is a small sample size.
Things to note:
Small sample size
Outliers abound (Jake Brown I'm looking at you)
The average MIAC finish for mortals in their first seasons is - 13th or so (not including Austin who didn't race it)
The average MIAC finish for esteemed alumni in their first seasons - 4 -5th
Average MIAC finish all together - 8 -9th (not including Austin)
SO, you're right. It was a bit of a jump, based on these numbers, to say that he is the favorite to win MIAC this year in the steeple. BUT, his debut steeple is the fastest out of everyone listed here excluding Ryan Peterson who ran it as a junior. That has to mean something.
I'm sticking with my prediction of 9:20's for Wilkinson.