For the question as to the non-top 10 Celts... yes, Paul Silas is my man ... rebounder extraordinaire, best defensive stopper of all time, no offense to the Bowens, M. Coopers, and Rodmans of the world.
Ok, if you're convinced that Howard, without another elite PF defender is good enough, then sure, it's either Larry or Hondo for me. I still believe in defense so my nod would lean towards Havlicek, simply because he was completely solid on the perimeter, defensively, and was a terrific scorer all around. Plus, I think his running would take LeBron, Wade, and Kobe out of breath after 3 quarters, since the NBA doesn't allow for juicing for Q4
I think I have an intrinsic love for the central 70s team because for the most part, when Silas-Cowens-Havlicek were together,'72-'76, we never had a losing streak of any sort. You can look this up, I believe there wasn't a period of 3 or more losses ever. There were two injuries, Havlicek's elbow in the '73 playoffs and Cowen's ankle in '75, which stopped nearly 4 seasons of straight titles. As a whole, the 70s unit were the defensive masterminds of the age and really showed that crafty defensive, with everyone contributing offensively (now including the likes of Westy, Chaney, & Scott), won championships.
The current crop of C's, I believe, were not that great at defense because despite scoring slumps, we gave up leads, more often than not, by losing focus and tenacity. This seemed to happen too often for my comfort. I mean the Lakers did win the rebounding contest in game 7, and in my scenario with Cowens (or Silas), we win it. And likewise, with Hondo, I don't think RonRon will be able to hang with him for more than one quarter. RonRon doesn't run marathons on his free time.