Uhh, I think it is most of your post that has no basis in fact.
First of all, Philadelphia was not a top 10 level defense by any stretch. The ranked 20th in points allowed, 15th if FG% allowed, and 24th in pts per shot allowed. They are a mess offensively and only slightly less of a mess on defense.
Secondly, it is hard to say the team got better as the year along. Here are their 10 game win-loss splits for the second half of the season: 4-6, 1-9, 5-5 and 0-10. The only way you can say the team as a whole got better is if you conveniently overlook to 0-10 stretch to end the season and the 1-9 stretch back in January/February.
I don't know much about Jerami Grant, but I find it hard to believe that someone who shot 33% from the field (26% from 3 pt) after the all star break is someone who has found his shot.
Pretty much the only thing you got right is that Brett Brown has been good for the 76ers considering what he has been given.
So I was slightly off: Sixers ended the year in a tie for 12th in defensive efficiency:
Rankings Just looking at PPG allowed is silly: by that metric the Warriors would be a decent defense, not the league's best unit (which they are when factoring in pace).
Again, it's pretty clear what the identity is now and will be going forward. Brett Brown has talked about how everything will start with defense, Hinkie has talked about how it's arguably more than 50% of the game, etc. Since Hinkie seems to be a forward thinker, he's probably planning his future acquisitions once they start "trying" to win around gathering as many athletic guys as possible. Reason being that in order to keep up with these new "pace and space" offenses defenses will need to be able to switch aggressively like GSW and MIL (not coincidentally the two best defensive teams this season).
Last 10 games sucked (and they clearly decided to tank to ensure that LAL couldn't pass them in the standings) but prior to that they looked OK after that 0-17 start. Shoot, they lost quite a few games in OT/last possession situations: that's significantly different than being crushed by 30 every night like the Knicks.
RE: Jerami Grant: he tailed off, but considering he only attempted thirteen 3 pointers in two years at Syracuse should indicate that he's made progress. I consider that a win from a development standpoint, because he could actually be a useful player with his athleticism if he's just decent shooting. And FWIW, I'm pretty sure his shooting numbers are better than KJ McDaniels.