Disclosure: current MD student at WashU
The most important detail left out here is arguably price! You will do great from all the programs, so go where its cheapest.
To address some of your cons for WashU:
1) Why would distinction be a con? Not getting a distinction won't hurt you, but getting one can help set you apart in the residency application process.
2) Downward trend in ranking? Among program directors? On admit? Outside of pre-med spaces the pedigree of WashU has not changed meaningfully in decades. It continues to be one of the best medical schools in the country and is generally "ranked" above the other programs listed here.
3) Difficulty matching outside of Missouri? Based on what? If we look at the last two match cycles on their website they matched 79 to the East Coast, 100 to the midwest and 60 to the West Coast, with Missouri (41), California (25), New York (13), Washington (7), Massachusetts (9), Pennsylvania (9) and Illinois (7) being the most popular states. The Missouri number is also inflated because many students match preliminary at Missouri Baptist (BJC) while simultaneously matching specialties (radiology, anesthesia, derm etc.) outside of Missouri.
4) Difficult to view this in isolation. Yale matched 4/12 in derm despite having a T5 derm residency program. So many factors at play here including the quality of the applicants, application strategy, geographical preferences etc.