Yes, we know that Thomas's stay in Boston lasted only two years and change, but he was on fire, especially in his last year, and was the man who carried Boston further than they had any right to be at the time.
Ainge actually played for the Toronto Blue Jays before he was drafted by the Boston Celtics, who chose him 31st Overall in 1981. After a rocky start, he would find his role in professional basketball as a pesky agitator and occasional scorer. Ainge would help Boston win two titles (1984 & 1986) and was a bit of a surprise as an All-Star in 1988. The Guard averaged 11.3 Points per Game over the seven-and-a-half seasons he played for Boston.
Reggie Lewis was a late-round draft pick in 1987 and the product of Northeastern University, playing less than ten minutes a game as a rookie, so it surprised some when he would blossom when gaining minutes due to Larry Bird's injury and had an 18.5 PPG season as a sophomore. Lewis would become the starting Shooting Guard, and in 1991/92 and 1992/93 he averaged just over 20 Points per Game, with the first of those seasons earning him All-Star recognition.
Bailey Howell had already been to five All-Star Games (four with Detroit and one with Baltimore) before he arrived in Boston for the back nine of his career. Howell wasn't putting up the exact numbers he had in Boston, but he was now on a more loaded team, and when you are a teammate of Bill Russell, you don't have to lead the team in boards. Howell was a strong presence during the NBA Championship wins in 1968 and 1969 and was chosen for his sixth All-Star team the year before he won his first title. Howell would average 18 Points and 8.4 Rebounds per Game with a 17.9 PER.