Good question. In another forum someone made a VERY good case that QS is more powerful than DM based on WS being able to do things during the Cosmic Armor SM event that DM was unable to do.
Personally - I consider them the same being. Yes, I know different creation stories, that they are literally different people (Allen and Jonathan), but I consider QS a dressed version of DM; and DM a naked version of QS.
The same person - kind of like how I personally believe Mr Mxy.... and Bat-Mite are the same being.
Beings so powerful that they can split themselves, even to the point of going back in time and creating split creation stories. Considering how QS for example described how he sees our world (when he pulled a DeadPool and started talking to the reader), and considering just how power QS and DM are (in some ways even more than Mxy and Bat-Mite), my personal theory is that Allen and Jonathan are different aspects of the same being.
Kind of how Hindus believe in Brahman, who is three in one (Brahma, different from Brahman; Vishnu and Shiva) ...I could use the Christian Trinity, but let me not.
It’s my theory, it will never be proven since it’s a bloody comic book and tomorrow DC could merge with Marvel and the writers can say that the Watchmen Universe was a creation of Franklin Richards and that the entire DC Universe was a dream Logan had when Sabretooth knocked him out.
As in, writers can write whatever they want.
But my personal pet theory - in the same way, to me, Mxy and BM are the same person; QS and DM are the same person living through different realities.
So, they are equal.