For sure, the Lakers' bigs are no joke. They were certainly the #1 reason the Lakers were champions at the expense of the Celtics, but I somewhat understand the sentiment of the original post.
Teams need skilled bigs in order to win against the Lakers...that much is true. That's why I never even entertained the idea of OKCity taking the down in the 1st round last year. However, teams don't need the SAME types of bigs that the Lakers do...and that is where the Celtics come in...
...and as usual, it simply all boils down to KG. The national media has largely forgotten KG's (true) impact on the Celtics....because his credo is help defense, and that is something that is hard to put into basic stats...one needs to actually watch him on the court to see his impact. Shaq is no slouch either. I would argue that at one end of the ball, a KG-Shaq pair is instantly MUCH more potent defensively than any Laker big combo out there. There really is no disputing that. This team was 1st in defense for the first half of the year with THAT very pairing (and Shaq wasn't even consistently in the lineup during that time!).
And has everybody forgotten that the Lakers as a WHOLE rebounded well in game 7?...not just the bigs. How many rebounds did Kobe have?...15! The Celtics did a p--- poor job of gang rebounding in game 7...and I'll hand it to Kobe...he did what superstars should do...despite a horrid shooting night, he came through on the boards.
This is where the Green acquisition comes in. Already we are seeing it's effects on Paul Pierce's level of play...just phenomenal. You get rest for Paul and Ray...you get consistent offense, and consistent gang-rebounding. Just watch back to many of the most significant games of this year (spurs, magic, lakers, bulls)...the gang rebounding by these two, especially Paul, excelled.
Add in a healthy Shaq, a 10 minute Jermaine, Kristic, the KG/Baby tandem, and the 3-2 Paul/Ray/Green platoon...and YES, I think the Celtics will do just fine on the boards against the Lakers. In summary, the Lakers' length IS as real as it is vaunted, but it doesn't necessarily have to be copied in the same exact way in order for teams to be successful.