With ADP R-D and R-D-D, generally the root part and the container have the same owner by default. After the initial ADP config on controller initlization I don't think it matters though. I've always tried to keep them balanced though.
with R-D "The container disk and the two partitions do not all need to be owned by the same node in theHA pairas long as they are all owned by one of the nodes in theHA pair. However, when you use a partition in an aggregate, it must be owned by the same node that owns the aggregate"
I usually recommend to customers to do a "reallocation start -f true -p true -path /vol/volumename" and do one volume in the aggregate at a time. Usually that is enough to balance it out. Start from your busiest volume that may be the smallest and work your way to more idle volumes.