What faction?

I plan on playing on this server but I want to play the least populated faction to help give them a fighting chance, what one should I play?

Alliance is the underdog

According to all available statistics Alliance are the dominant faction on Felstriker.

Personally though I would just play what you enjoy. I’m Horde because that’s what my friends rolled with on release, but honestly if I had to choose a faction from Vanilla Alliance is my favourite.