DarkOddity: sorry, I didn't answer your question there.
You COULD do so, I assume. Beat down the Nomads, then beat down the Order, then beat down the other factions to even up your reps. I guess if you did that and mostly confined your beatings to the unpopular human factions after pleasing the Nomads, it could work: it's not like you could piss the Order off any more than you already have by buttering up the Nomads. But as soon as you started hitting the Order again (likely while moving through the Omicron Systems to off-load human cargo at a Nomad base for even higher prices than usual), you'd be quickly back to square one with all the humans hating you. Some advanced cruise disruptors in the Order's fighters would make getting away from them without a fight VERY difficult.
So, yeah, it's possible. But you'd be working harder to make less money if you did so and then confined yourself to the House Systems to keep your rep system from falling apart (which it would at first Order contact). Best prices for pilots in the houses are Bounty Hunters at Arranmore, and that's a far cry from 28,000 for a Nomad at Cambridge Research Station. You'd make more without having to be careful about it just stomping Nomads for the Order.
Here's a thought: the Nomads would be looking for a way to re-infiltrate the colonies after their defeat. For these hypothetical high-end Human-traitor players, add a commodity called "Nomad VIP" (Or "Nomad Spy") that can only be bought in Nomad Bases and must be brought to House Capital Worlds or perhaps Battleships for the best prices: "You'll be paid your "credits" when I'm safely on Manhattan, Host - the small retainer you paid us is to ensure your loyalty."
How's THAT for smuggling? You'd be tempted to return to the Nomad bases to off-load your human prisoners and then load up on Nomad VIPs or Spies to make the run back. In or out, you're fighting the Order either way and chancing the upset of the whole rep balance you've cultivated. Makes the end-game very high-stakes if you want to play both sides. Big risks, big rewards!
