I often look at casting too literally, and feel it boils down to the actors, contracts and the like.
However, I agree with you. I think that if it was him in the wheelchair, with Bree, it would be just as entertaining (if not more) as Bree and Orson. Plus, another avenue would have been him feeling too self-defeated to practice law, and for him and Susan to partner up to make the strip club a financial success so as to protect his livelihood/Julie's inheritance.
Can you just imagine Bree with him AND him being an active partner in the strip club? That would make for some good scenes, IMO.