Heat bacon drippings in 6-quart Dutch oven or stockpot over medium heat. Cook and stir ham in hot bacon drippings until slightly browned, about 5 minutes. Add chicken and potatoes to the pot; cook and stir until the potatoes soften slightly, about 5 minutes. Season the ham mixture with thyme, marjoram, onion powder, and garlic powder.
Pour cans of whole kernel corn, cream-style corn, and chicken broth into the pot. Stir milk into the mixture. Bring the liquid to a boil, reduce heat to medium-low, and cook at a simmer until the potatoes are completely tender, about 10 minutes.