One word - Modding. I don't know about multiplayer, but you can mod the game to play as a Nomad ship in single player. So you can probably do the same to multiplayer. Check the modding forum. Sorry that I wasn't much help...

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Knock, knock
Who’s there?
A talking pig.
Pigs can’t talk.
Neither can penguins, but I can’t shut him up[[! Wait till you get a load of the dancing candelabra…

To be honest you should probably play SP through and find out what the nomads are that way. I'm not saying 'nah nah i'm not going to tell you' i'm just saying it might ruin SP a wee bit for you. So i'll write it backwards... read it if you like

.dom a edistuo eno tolip tonnac uoy dias 'oidaR ekiL .snugs ssa drah tub sdleihs oN .cte tnemnrevog etartlifni dna yrt ot seidob snamuh revo ekat taht noitazilivic neila decnavda morf spihs-oib erraziB = rethgif damoN

!rethgif damon fo noisrev ssa giB = pihselttab damoN

If i wasnt so stupid i could just have made that a small font or changed the colour or something