It's pretty ass-backwards to cleanse Cashman of any blame for the Yankees' many garbage big-ticket signings, and then turn around and wholeheartedly s*** on AA for the Marlins trade, but even if you let that slide, anyone who thinks Cashman would be a better GM for the Jays than AA based on only what we know, is, as rjf so eloquently put it, talking out of their ass.
Anyone that talks s*** about the Dickey trade, I'd love to see them justify the time when Cashman also traded for an aging pitcher after contending for a Cy Young award, and gave up Jose Contreras for half a year of below replacement production from Esteban Loaiza. For the people that love to talk about how the Jays gave up a s*** ton in exchange for less in the Marlins deal (which is still paying off for them), I'd love to see them justify the Yankoffs trade of Jackson (15.6 war in the 5 years since), Kennedy (13.6 WAR in the five years since), and Coke (1.1 WAR, 1.8 WAR in the two seasons after the trade) for Curtis Granderson. Everyone loves to lick the Yankees balls and say that it was a win-win trade, but it wasn't. It was a s*** trade. Ajax alone was worth more for the Tigers than Granderson was for the Yankees in the exact same amount of time.
The Yankees have a garbage farm system, and they've had a garbage farm system for years. Since AA took over for the Jays in 2009, the Yankees have converted an entirety of two top prospects into regular major leaguers in Ivan Nova and Dellin Betances, who struggled for years as a SP prospect before finally putting it together in the pen. The last good guys to come out of their system were Gardner and Robertson, back in 2008. The only other top guys from their system in the last seven years were literally all traded to the Tigers in the Granderson trade. They've gotten nothing out of Gary Sanchez, they've gotten nothing out of Mason Williams, they've gotten nothing out of Bichette, and the "Killer B's" were an utter embarrassment until they caught lightning in a bottle and Betances finally emerged from the pile of steaming s*** to become a relief god.
The Yankees are atrocious at signing free agents to long term deals, they suck at developing their own players, they don't have a good track record with the guys they've extended, and their good to bad trade ratio can't be much better or worse than the Jays. They have decent depth from time to time, but that's because every old f***er in the game wants to play for the Yankees before they retire, and so they get to squeeze marginal value out of guys like Ibanez, Jones and Ichiro on cheap contracts.
I don't think AA is the best GM out there. I actually think that there are probably a host of executives out there that might be better for the job than he is. Having said that, the chances that the Jays actually go out and sign someone better than AA for the job are so slim that it wouldn't surprise me at all if the same people begging for him to leave right now are eventually bawling their eyes out when the Jays replace him with someone like Stewart or Minaya.