User blog comment:Warmachine375/Gun-Gun Weapons possibility?/@comment-73.136.18.37-20150530152820/@comment-25555436-20150530214414

It's like in some videogames, where some things are designed for a certain purpose or strategy, but players find out later it can also be effectively used for another purpose or strategy.

I found an example from Final Fantasy XI. The Ninja class was supposed to be an Assasin-type class, striking from behind to deal great damage. However, thanks to it's great evasion and a skill that created damage-absorbing shadows, it was also one of the best tank classes in the game.

Basically the same here. The Elephant was meant to be a mobile repair station and heavy transport, but it turned out to also be an effective tank thanks to it's armor and size, so the UNSC used it as such too when normal tanks were not available or wouldn't be as effective.