I must be missing something here.
When you have a great offensive pivot, a guy who attracts a lot of attention in the half-court, hasn't the best combination been to plug a 'rugged', defensive rebounding big next to him who can occasionally hit the mid-range jumper and play smart? This is supposed to be the guy who will body up on the other teams primary big on defense and keep the other team honest on the offensive end.
For example, Horace Grant/AC Green next to Shaq, or Robinson next to Duncan (and Oberto/Nazr/Rasho to a certain extent), Otis Thorpe and Olajuwon, Oakley with Ewing.
Scola will definitely help with taking offensive pressure off of Yao. But the tough, defensive presence? As has been indicated, not bloody likely.