I always brown up my sausage and meatballs in the pan before I start adding the the rest of it.
After you get the main sauce going, you put the meats back in and let it cook for a few hours.
Brown them, then I put a little red wine in there to deglaze and get all the yummy brown bits that stick to the pan, then you can add that to the sauce since it will need a little red wine anyway.
My wife does what her mom used to do- makes meatballs, browns sausage, and also adds browned bone-in pork ribs. Cook all that in the sauce….oh, man…..
Oh, I have to say, the wine in the sauce is a MUST, and it should be a nice Chianti (no fava beans)!
Meats browning first is a great idea b/c you get all that unctuous meat glaze on
the pan bottom that incorporates into the tomato sauce when added and simmered.