Answer
The practical split most carriers land on is hybrid. Dispatch and rating stay native because that is where the correct, hard-won logic lives and moving it carries genuine operational risk. Rate shopping, document capture, driver mobile workflows and analytics go somewhere newer because those are additive and can fail without stopping a truck. Decide which side of that line each capability belongs on before a vendor decides it for you, and ask any vendor claiming a native IBM i product to name reference accounts on your IBM i release.