An upgrade to LC + is a good idea - I may stand corrected, but I believe they come with a larger motor than just plain LC and, while an LC starter set engine may initially pull a long consist for awhile, the question becomes how long that will continue before the motor starts to deteriorate and eventually fail.
Check this thread and the imbedded videos for more info ..... Pulling Power of LionChief+ and LionChief | O Gauge Railroading On Line Forum (ogaugerr.com)