Boomers and remnants help together at hoover dam

Hi,

I'm playing Fallout new Vegas for a while now and I try every storyline.

I've already completed thegame with the help of the boomers. Now i'm trying to get the remnants on my team. Thing is, to gain access to the remnants chapter of the game, I need to get at a certain point in the story. I'm following 'The house always wins' quest line. to get at this certain point, i either have to kill or recruit the boomers.

So is it possible to have the boomers and the remnants helping you at the final battle together? Or do I have to kill the boomers in order to get the remnants on my side?

Thanks in advance,

Tyrone