I actually think starting Shaq would be more valuable against Orlando than against the average team, because:
1) Shaq also does a good job on Howard 1-on-1. With his size and strength he is able to keep Howard from his spots as well as anyone
2) More importantly, on offense Shaq
a) forces Howard to respect him instead of playing help defense. The importance of that can't be overstated, as Howard's help defense is the crux of their interior defense. No more Howard shutting down Rondo's driving lanes with impunity. No more Howard leaving Perk to help Lewis against a posted KG. With Shaq on the floor, Howard has to stay home, which is huge.
b) Shaq can draw fouls. If Shaq can get Howard into foul trouble, which is actually a reasonable bet, it changes the whole complexion of things.