There are plenty of people who let their animals interact with each other. Me included. The trick is simple - use common sense - if someone is cranky it might be a good time to keep them separate. No one knows their pets better than you. You know the moods, the temperament, and when the time is right.
Ellie May is wonderful! Has anyone told you lately that she looks like she's been swiping someone else's meals? :-D You should see our TN mountain cur mix and the terrier mix. They can no longer even scratch their own butts! The three pits and the rottie mix keep each other trim...and the chow is in with the first two. Eats way more than her share!
I bet I have the only bloodhound who eats collard, turnip and mustard greens!
Well then...I have the only pit bulls that do as far as I know. Two of the three beg for the stems - and the one I call our ADHD pittie will "sneak" the leaves out of the pan I cut them into while I'm looking right at her. She seems very proud of herself that she does this... ;D