The obvious solution is a top 10 protected first in 2020 + Domi for both.
While it is probable the first is indeed top 10, I think a line-up with a backend like:
Dumba-Brodin
Petry-Romanov
Weber-Chiarot
is quite unlikely to miss the playoffs. Could be wrong, though. Weber-Chiarot would be a heck of a 3rd pairing.
Still think the most realistic trade is Domi for Dumba, straight up. Brodin is a less attractive target, but would be doable with an extension attached after July 1st.
Will Toronto be able to pry Dumba before the deadline to help'em in their push this year? That is the great question. They don't have a top 6 C to spare, however.