If both the Dovii and Jag are male, there will be mahem when they get around 5". If there is a male/female combo, they might bond, but the larger will likely end up killing the smaller. If you get the jag and dovii when they are both around 1", there is a small chance they will grow up together in peace, but avoid feeding live food else bring out the aggression in the fish.
If you put a divider in, you can entertain yourself watching the fish flare up at each other w/o injury to fish. If you have a male dovii, he will outgrow your tank eventually.
To answer your question, don't waste time on plants as both these fish are avid diggers. Rocks, caves, and hiding places are great for these fish. Wood is a matter of preference. They are both fairly tolerant of water conditions so just avoid extremes and your fish will be happy.
I don't want to sound negative (because believe me, I try all sorts of weird stuff), but I just want you to watch out for potential problems you face with your proposed set up.
Good Luck!