Brown ground beef and onion in a large skillet over medium-high heat for 8 minutes, breaking the meat into small crumbles and cooking it to 160°F. Drain excess fat.
Transfer beef and onion to a 6-quart slow cooker. Add smoked sausage, potatoes, pinto beans, baked beans with sauce, tomatoes, corn, broth, paprika, garlic powder, salt and pepper.
Stir thoroughly, cover and cook on low for 6 hours until the potato centers are tender and the stew is hot throughout.
Mash a few potato pieces against the side of the crock and stir them into the broth if you want a thicker finish.
Stir in cider vinegar and rest uncovered for 10 minutes. Divide among 6 bowls with both meats and beans in each portion.