First things first. Robinson measured out in shoes at the combine at 6'8.75". OK, can we agree that he's not 6'10"... The question is, can he guard PF's? To say he can guard the Morris Twins doesn't cut it. The question should be, can he guard LaMarcus Aldridge, his current teammate. How about Dirk Nowitzki, or even Ryan Anderson, who is a legit 6'10". JT can, and more often than not, does a credible job on those players. But then JT is 6'11"
Not to pick on you Baja, but I see this line of thinking so often that I don't think it should be allowed to stand uncontested. I listed every starting PF in the NBA right now and their measured height
without shoes on (because I don't think it's fair to penalize a player for wearing shorter heels to pre-draft camp) plus some key bench guys and/or former starters. The
bolded players are the ones significantly taller (an inch or more).
Thomas Robinson measured as
6'7.75" without shoes...
STARTERS:
Atlanta Hawks - Paul Millsap 6'6.25"
Boston Celtics - Jared Sullinger 6'7.75"
Brooklyn Nets - Kevin Garnett ~6'10" (38 yrs old)
Charlotte Hornets - Marvin Williams 6'7"
Chicago Bulls - Pau Gasol ~6'10" (34 yrs old)
Cleveland Cavaliers - Kevin Love 6'7.75"
Dallas Mavericks - Dirk Nowitzki ~6'10" (36 yrs old)
Denver Nuggets - Kenneth Faried 6'6"
Detroit Pistons - Josh Smith 6'7"
Golden State Warriors - Draymond Green 6'5.75"
Houston Rockets - Donatas Motiejunas ~6'11"
Indiana Pacers - David West 6'8.25"
LA Clippers - Blake Griffin 6'8.5"
LA Lakers - Ed Davis 6'9"
Memphis Grizzlies - Zach Randolph 6'7"
Miami Heat - Shawne Williams 6'7.25"
Milwaukee Bucks - Jabari Parker 6'7.5"
Minnesota TWolves - Thaddeus Young 6'5.75"
New Orleans Pelicans - Anthony Davis 6'9.25"
New York Knicks - Quincy Acy 6'7"
Oklahoma City Thunder - Serge Ibaka 6'8"
Orlando Magic - Channing Frye - 6'9.5"
Philadelphia 76ers - Nerlens Noel 6'10"
Phoenix Suns - Markieff Morris 6'7.75"
Portland Blazers - LaMarcus Aldridge 6'10"
Sacramento Kings - Jason Thompson 6'10"
San Antonio Spurts - Tim Duncan 6'11" (38 yrs old)
Toronto Raptors - Amir Johnson 6'7"
Utah Jazz - Derrick Favors 6'8.75"
Washington Wizards - Kris Humphries 6'8.25"
BENCH:
Tristan Thompson 6'7.5"
David Lee 6'7.75"
Julius Randle 6'7.75" (starter before injury)
Carlos Boozer 6'7.75"
Udonis Haslem 6'7.75"
Ersan Ilyasova 6'7.75"
Anthony Bennett 6'6"
Amare Stoudamire 6'8.5"
Aaron Gordon 6'7.5"
Carl Landry 6'7.75"
Trevor Booker 6'6.25"
Nene 6'9.25"
So 12 out of 30 teams currently employ a starting PF who might have a height advantage on Robinson. One additional team has a key bench player who might have a height advantage. Out of those 13 players, 4 are very close to the end of their careers (Duncan, Garnett, Nowitzki, Gasol) and shouldn't really factor into long-term planning anymore. 6 more are not significant post-scoring threats (Motiejunas, Ed Davis, Frye, Noel, JT, Favors). So who are we really afraid of here?
Anthony Davis, LaMarcus Aldridge, Nene. That's it. When you're talking about "can't physically handle this guy in the post" -- that's the entire list.
There are two guys who didn't quite make the 1" cutoff. Both
Amare Stoudamire and
Blake Griffin are listed as 6'8.5" without shoes on which gives a slight height advantage. But does that even matter? If you think it does, I would take it one step further. Robinson has a wingspan of 7'3.25" and a standing reach of 8'10". That means just standing on the ground with his arms in the air, he's got his hands higher than Blake Griffin does at 8'9". Stoudamire is hardly worth worrying about at this point in his injury-hobbled career.
You specifically mentioned
Ryan Anderson who I couldn't find a measurement for, but if he's listed at 6'10" we can assume he's around 6'9" without shoes. About the same as Anthony Davis, Nene, Channing Frye, and Derrick Favors. Anderson is a threat as a shooter, not as a post player so an extra inch of height is a lot less important than the ability to run the floor and stay close enough to contest his jumper. A similar argument could be made with regards to the way Anthony Davis and LaMarcus Aldridge score most of their points. You're going to have to be able to put an arm in their face from 10-15 feet out and outmaneuver them on the floor. Speed and guile are bigger factors defensively against them than an inch of height. Not to mention, both of those guys are top 10 scorers. Nobody else is doing a good job of guarding them either.
The myth of the 6'10" power forward post-monster should really be put to bed. There aren't any left. A quick survey of the league shows 6'7.75" without shoes is damn close to the median height for the position right now. And if you've also got long arms and above-average athleticism like Robinson does, it's not going to be physical tools holding you back.
Furthermore, it would be an advantage, I think, to
retain Jason Thompson (one of the few PFs in the league who doesn't have a height disadvantage on anybody and has done a good job bodying up post scorers) and compliment his defensive skillset by adding a smaller, faster player who stands a better chance against the more perimeter oriented PFs which currently dominate the league. In terms of mobility and size, very few players are as well-equipped as Thomas Robinson to handle that role. Obviously he needs coaching, but even in limited minutes his steal rate, block rate, and rebound rate are all better than average so I don't see how anyone can say he's not
physically capable of getting the job done defensively.