FTL Reactor - Misnamed or misconceived?

As we all know, in Halo Wars the Shaw-Fujikawa Translight Engine is misnamed the FTL Reactor which means the Spirt can go faster than light. Which, in Einsteinian terms is impossible; as it requires infinite energy. Then howcome the UNSC has managed to travel to different Star Systems? They managed to find away around Einstein's theroy of Faster Than Light travel. Yet, the UNSC has and hasn't. They have, because of an alternative way of going faster than light. Slipstream Space, or Slipspace to us hardcore fans. Anyway, what my limited knowledge of Slipspace tells me that, it creates a black hole and then somehow allows the traveller to faster than light in one of three demtions. However, Halo Wars is the only game, the only member of the Halo franchise to misname the Shaw-Fujikawa drive. Surely they must have understood that it isn't FTL, or maybe they were trying to appease the younger and less devout fans of the franchise, by making it simple. Because if a 14 teenager can figure this out, isn't it certain they can?