Each UY is its own membership. It will be like being two different owners.
To use the points together, you will have to transfer. Once transferred, they still retain their own rules so you need to be strategic to ensure they can be used for the trip you want.
Currently,
DVC allows owners to transfer between their own memberships more than the once per UY transferring rule in place between different owners.
We have multiple memberships but we just book whole nights on each vs transfers. We also use for different trips so we don’t combine.