Pretty bizarre comparisons. Robert Parish to Gortat and Danny Ainge to Dellavedova?
Cool hypothetical exercise, but a big part of the problem seems to be the author spends too much time trying to match the age and stats instead of the talent.
Like with Ainge/Dellavedova, the author uses Per-36 to match up the stats, but there's a couple of problems with this. Dellavedova has never played 30+mpg in any season ever, and has never averaged more than 7.6ppg, while Ainge routinely was averaging over 30mpg and putting up 15-20ppg during his prime. So he's comparing a player in Dellavedova who was probably getting 120% out of what he was capable of producing vs a player in Ainge who was contributing maybe only 60% of what he was capable of. If the C's needed Ainge to step up one game and give them 20, he could do it (including playoffs). If the Cavs needed Dellavedova to give them 20 one game, well then they're taking the L. This is further demonstrated in the playoffs, where Ainge was able to step up and give 36mpg and 16ppg, while Dellavedova went down to 12mpg and 4ppg. (To be fair though, looks like article was written in Feb before Dellavedova's minutes/role decreased, which were partially juiced to begin with by Kyrie missing the first half of that season).
Similar issue with Parish/Gortat. Parish's 16/10 were what, 70%-80% of what he was capable of at 32? After all Parish was able to step up and give 18.5ppg/12.5rpg at age 35 in '89 when Bird played only 6 games. Gortat on the other hand, that's the max he can give, and that's only possible on a .500 team (or worse).
It's like comparing '12 James Harden averaging 17/4/4 (on a winning team, behind Durant and Westbrook) with '09 Nate Robinson, also averaging 17/4/4 but on a bad team. Both scoring guards with no D coming off the bench putting up very similar stats, but it's not the same talent at all.