As much football understanding as a doorknob
Since you may be ignoring the above...
Tom Mitchell will retire with more Coaches votes, more Bronwlow votes, more B&F's, more All Australians, more MVP's, more of the ball, more tackles, more clearances, more of every individual accolade the game offers from fewer games than Trent Cotchin.
But Cotchin is the better player because his team won 3 flags, even though Cotchin did not win an individual accolade of any description in any of the flag years and did not finish in the top 8 of the B&F in either 2019 or 2020 (and was almost a liability in the finals of those years, as highlighted above).
Cotchin was a very good player and was/is captain of one of the great sides but being part of a great side deos not make him a better individual player than Tom Mitchell, as the above clearly demonstrates.