ALLEN PARK — The time has come for the Detroit Lions to end their rotation system at running back and play Kevin Jones on a full-time basis. One of the biggest mistakes of the regime of former coach Steve Mariucci was pulling Jones in third-down situations. Mariucci gave a lot of reasons for it, but none of them made any sense. Whether it’s a boring West Coast offense or a high-octane downfield attack, it is always more logical to have your best players on the field at all times.