Yes. Okafor's ceiling is Cousin's offense with worse defense due to his lack of athleticism. No one can sell me that he'll change that. Just look at Kelly O, who has worked his butt off to only marginal improvement and Sully, who hasn't worked at all and still has a large behind. Cousins is also locked up and young (24). In fact, age-wise, Cousins fits more with our current group (AB, Crowder, Smart, etc.).
Take into account, however, that I have a great deal of faith in Stevens's ability to corral Cousins. Cousins's biggest issue in the league has been his weak mentality combined with even weaker organizational stability (the Kings have been sold, protested, been through 3 coaches, almost moved, etc.). I feel that coming to the Celtics with a united front office and a players' coach would do wonders for him.