I believe that many of you are, unfortunately, missing the point. Speaking for myself, I wrote here, right after Posey signed with the Hornets, that the best option would probably be to re-sign Allen and House and stand pat. But this doesn't mean one can't make an assessment of the strengths and weaknesses of our current roster. When people say that this roster is "risky" and has notorious flaws, it means precisely that, not that "we don't have a chance". That's a straw man argument, something civilized people don't use. Just saying one is silly to be concerned because "nodoby knows if a rookie can step up or not" is nonsense. That's precisely the question: not knowing if a rookie can step up or not. Saying it doesn't matter because the roster will chance before the playoffs it's something I don't quite understand as well: what's exactly the point? We are talking about what we need to do to improve this roster, as it's currently built. Or saying that Ainge didn't mis-calculated anything. How do you know? How do you know Ainge didn't gamble with Posey, missed his fallbacks while doing it and then Posey's agent didn't allow him to match the Hornets' offer?
Another fallacy is using an argumentum ad verecundiam. That's in very bad taste, IMO. Let me ask you something: do you consider signing another veteran, say, Bonzi Wells or some backup center, in the next few weeks:
1) a good move
2) a bad move
3) a good move if Ainge sings someone and a bad move if Ainge doesn't sign anyone
The point is: at this moment our bench lacks experience, size and outside shooting. I guess we can all agree on this, no?
Good points here, but the questions remain. Do we need another player with true length on the wing? Long arms and reach are nice, but 6'9" si still better than 6'5" at the end of the day if everything else is equal. For example, would a Linton Johnson type player be more valuable that a Tony Allen?
This brings up another question, we need a third backup center in some opinions. Should this guy be a beast like Perk? Should he be long like POB? The beast is the easiest to fill IMO with the Jackie Butler types out there.
Lastly, I dont think the veteran off the bench position is that important. I think just having a guy like Posey, Miles, Pollard, House, PJ, etc is most valuable because of the 'comfort level' he brings to the floor. These are proven performers, Doc and GAP trust them to make good decisions and a minimum of mistakes. This is one of the 'talents' that Scalabrine brings to the table.
Besides not risky, this type of veterans are known quantities. That makes everyone more comfortable. 
I'm not sure about anyone else but to me the body makeup and overall athleticism means less to me than does whether they can actually get the job done or not.
For example, if we hadn't yet signed POB and knowing what we know about our needs in the middle, would you have preferred the long, athletic POB or the shorter, more productive and more experienced Kurt Thomas? Personally I think it's a no brainer. I don't care that Thomas is only 6-9 he is a proven 10 PPG and 8 RPG performer and has been against some of the best.
I think it was Vince Lombardi that first keyed the philosophy that as long as his team worried about doing their job they would win. He didn't how he matched up that was the concern for the other team. That mantra should hold true for any championship caliber team. Go out and perform and play your game. Let them worry about the match ups.
That's why I don't buy into the whole "we have to go out and get more athletic" philosophy that Doc and Danny are spouting. Drafting players that fit your system and picking up players who's known games can be used by your coach within his system is a more important aspect of player management. If the player happens to be very athletic, great.
So, Danny went out and got a bunch of athlete's, most with questionable games. Even the most positive of supporters has to agree there are a lot of question marks in the guys Danny brought in. Yes, they are all athletic, but can they be productive and do their games fit into the Celtic's system?
Would you rather have a Kurt Thomas or a POB? Would you rather have a James Posey or a Darius Miles? Would you rather have had a Tony Allen or a Delonte West? Athletic doesn't mean better!
Your point is well-taken, but you are also assuming a couple of things:
1. The available free agents out there that "fit the system" are productive and worth signing
2. The athletes that "don't fit the system" are not simply better talents overall
I don't buy the "system" argument at all. I think systems are built around the personnel. I also believe that Ainge and Doc both wanted more offensively talented players who could attack the basket more often. I don't think Doc wanted an "all jumpshot" team on the floor as much as he had to use.
I understand what you are saying but the Celtics do have a system in that they will be a defensively aggressive team and defensively agressive individually as well. There are a ton of players where this philosophy is not a part of their games and I believe rules them out as being attractive to Ainge. Players like Mike Bibby, Zach Randolph, Edie Curry, Dan Dickau, Gerald Green, Ben Gordon and many more are just players that Ainge would probably not ever consider bringing in now.
And you are right and wrong about my assumptions. First I used the players as I did as examples and not specifically because I wanted them here or thought that I think those would have been better additions. And you are right about your two points.
My point was that Ainge judges players first on their talent and their fit onto the team before they consider body type or athleticism at a particular position. My point being that if given the choice between a talented but less athletically gifted player and a more athletic player with less talent or more size that Ainge is going to choose the more talented player every time.
The UFAs this year weren't very good after the top few and others had already decided where they were going to be before they hit the market and Boston wasn't it. So given the dirth in talented UFAs, Ainge went for potential in athletically gifted players which were low risk and high reward. A very good strategy given what was available.
Of course, as I have said before, I would have prefered a different strategy that may have been more agressive for other players while writing off Posey early. I would like to have seen them go more in the direction of veterans that might have allowed them to play bigger, a style they played very well last year.