I think defense is tough to measure... My general stance is if you have an anchor and no absolute sieves then you are likely solid as a team. The guys that anchor the defenses should get the most credit for being good defenders. Rudy, Dray, Embiid, to a lesser extent Turner. The other guys just have to be competent and solid to have a good defense. I think Jeff Green and Bojan are good enough on that end that it won't sink the defense. Ed is smart and his on/off numbers last year were bananas... not sure he is that good, but he is good enough.
Perimeter guys like Danny Green are tough to measure as well.
One thing that will help the defense this year... Mike Conley's offense. He is a low turnover guy... Ricky was a high turnover guy... Those turnovers often turned into transition points because the defense isn't set. I also think having Mike run more PnR instead of Joe will help limit the team's turnovers. I think we slide a touch on defense, but that the offense is so much better that no one will complain.