In a large stockpot, combine whole chickens, soaked split peas, beef oxtail, and 10–12 cups of water. Bring to a boil, then reduce to a simmer for 1 ½ to 2 hours until chicken is tender. Remove chicken to cool.
Add cabbage and onions to the pot, stirring to combine. Let simmer for 30 minutes. Add beef stew meat, if using.
Once chicken is cool, shred it, removing skin and bones. Set aside. Remove oxtail from pot.
Add diced tomatoes, V8 juice, white pepper, salt, seasoning salt, garlic powder, and black pepper. Simmer for 30 minutes.
Add carrots and cook for 20 minutes, then add celery and cook for an additional 15 minutes.
Return shredded chicken to the pot along with potatoes. Simmer for 25 minutes or until potatoes are tender. Add green beans during the last 15 minutes if using.