Thanx NG for a super summer topic.
I agree about the relevance of scoring and statistical numbers, championships, years played and so forth for these guys to be considered Celtics. These are things that should be weighed in ones mind before the honor is bestowed.
Another factor for me is more spiritual. KG is passionate about being a Celtic for example. He was passionate about playing for the Wolves, no doubt as well. The thing is, he has given his heart and soul to the Celtics team, city, and franchise. He is 'all in' here on a different level than other players. Other examples of passionate people who happen to be Celtics no matter the length of time (in my view) include Glen Davis, Nate Robinson, Kendrick Perkins, and now Shaq.
I am sure Ray Allen cares just as much about the team as KG, but he is percieved as a much smoother character. He is easy to overlook when listing players if one is not careful beacuse of this personality trait. This of course does not make him any less relevant as a Celtic player, just different.
Some other short term people seem more like hired guns and we cant consider them no matter their performance. This becasue we value loyalty above some other attributes. The easiset example of this is James Posey. A big factor to be sure in our last Championship year, but absent from this discussion. Was he any more or less valuable than Bill Walton? Certainly he was/is a passionate intense guy at times.