You have got to be kidding me. Micheal Finley is done in every aspect of the game. Any team who gives this guy a contract is a sucker. Finley just cannot play the game at this level anymore, simple as that. I'd much rather have Tony play all the back up minutes for Ray and Paul than put Finley into the mix. Also, Finley is too small too guard most 4's and power 3's in the league.
Finley would be a backup 3 on this team, so his inability to play against a 4 and a 1 is irrelevant. Maybe Tony Allen could guard Shaq? That is about as relevant a discussion point.
Finley is as equipped to play power 3's than a 6'4" Tony Allen.
The fact that you said Finley is better than Tony Allen makes me glad you are not affiliated with the Celtics organization.
Please provide any link of evidence that Tony Allen is better other than the "consistent" overrating of his play. His turnover percentages are about 3X's Finley at his point in his career. If Allen were to accept his poor dribbling skills and not drive to the basket consistently turning the ball over, he'd be a better player than Finley. Since he doesn't and has the alarming turnover percentage he has ... it makes him a worse player. Suggesting otherwise is simply looking at Allen with rose colored glasses rather than seeing his shortcomings for what they are.
Michael Finley is 1/2 the player he used to be. Tony Allen isn't even that until he harnesses his extremely low basketball IQ and stops creating opportunities for the other team.
Unfortunately, if Tony stopped dribbling, he might be an even worse player, as he has no perimeter jump shot either.
Finley is an interesting option. Offensively, he almost entirely replaces Posey, since he can train the three like Posey. Defensively, as many of you already said, he wouldn't be able to do everything Posey did, but we wouldn't really need him to. If he could just be around to provide a little aid on some bigger 3s when Pierce isn't in the game, he could be useful.
Unless anyone really has any faith in Darius Miles or someone like that, I can't really see how it hurts to sign him. If midway through the season, someone becomes available in a buyout, we could always just cut someone on the current team to make room.