Heat olive oil and butter together in a large saucepan over medium heat; cook and stir sausage and onion until onion starts to brown, about 10 minutes. Add garlic; cook and stir until fragrant, 1 to 2 minutes.
Mix green bell peppers, zucchini, tomatoes, chicken broth, rice, Worcestershire sauce, and bay leaf into onion-sausage mixture; bring to a boil. Reduce heat and simmer until rice is tender and mixture is thickened, about 15 minutes.
Stir chicken and shrimp into tomato-sausage mixture; simmer until chicken and shrimp are heated through, 1 to 2 minutes.