DNA and trees

[HarrysMum]

Not sure if this is the right place to ask this but here goes…..
I have a paid Ancstry sub with my tree and DNA.
Hubby has his DNA on Ancestry but no sub or tree so we can’t see things like common ancestors etc. Not even sure how they work out which parent each new match belongs to.

What I want to do is somehow connect his DNA to my public tree so people can contact and/ or see a connection.
If that isn’t possible, is it possible for me to copy my tree over to his DNA as well without his having a paid sub?