Carrie,
Your explanation of leaning as a dominant behavior was excellent. I completely agree with you. I have 3 dobes, 2 lean. The oldest is 12 and I let her lean all her life as I thought she was "insecure", now that I know I still let her lean she is old and the kindest dog in the world. The second dog is a middle aged dobe who I recently aquired. I discourage his leaning and make him sit for attention. My youngest dobe 7 months is a nudger not a leaner. This we are working at discouraging too.
Kudos for your excellent definition of dominance.
Cheers,
Shannon