Soak the dried beans overnight, then drain and rinse before cooking.
In a large pot over medium heat, cook the bacon bits until crispy. Add the smoked sausage rounds and brown them slightly. Remove both from the pot and set aside.
In the same pot, cook the sliced onion until soft and translucent.
Add the fire-roasted tomatoes, all the beans, black-eyed peas, and split peas. Stir well.
Stir in the cayenne pepper, dried chili flakes, ground cumin, salt, and pepper. Pour in broth to cover everything.
Bring to a boil, then reduce heat and let the soup simmer for 1.5 to 2 hours, or until all the beans are tender. Stir occasionally and add more liquid if needed.
Return the bacon and smoked sausage to the pot in the last 15-20 minutes of cooking. Adjust seasoning to taste.