"Outside of Beni and Hanley" means that there was indeed evidence, for one. For two, a quick look at the Fangraphs stats department shows the Sox a mere +5.2 baserunning runs even though they were one of the best base stealing teams in the league, meaning the rest of their baserunning performance was lackluster. The Sox were boneheaded on the bases this year, and both stats and eye test agree.
That's just one area presented through quick research. I'm sure I can muster more proof regarding the Sox' overall problems with fundamentals.
Also, your point about them "not being the most talented team left in the playoffs" is a horrific strawman. Not once did I compare them to other teams. I said they overcame several fundamental mistakes to win their division because of their talent level. That was the extent of the statement, one I can pretty convincingly present as correct.