If what wikipedia says is accurate, and I don't put full stock in that, the Samnites can't hope to win militarily in the long run. But a short war will be to their advantage, not ours. They'd use a victory to seek better negotiating terms, while Rome's putting most of its military resources east.
But they're the faction most open to diplomacy.
We haven't specced for military actions. But, we can shore that up with the right men brought with us. We'll then have the change to get those military skills, and with some of Rome's best.
Now this? If we want to make our name, and in Shounen style? This is the choice to pick. If we can drill and trail the men hard, take a few back-line rolls, when the time comes for a decisive engagement, we can shock the world with fervent, disciplined soldiers.
While we'd be removed from the politics of Rome, we'd be throwing ourselves at the people who have one of the best claims for 'Enemy of Rome' The fucking Gauls. They have long memories, and they are extremely bitter. They will not care for oratory, but action. We can
show them that Rome is an ally, if we treat them fairly and firmly. And manage the fact Rome's ground them under its heel for so long.
If we go with the veteran legion or to Gaul, take this guy.
A greek would be useful over in Greece, but his charm will also help with the Samnites.
Take this guy if we're to be with the ninth legion. A skilled veteran and 'polymath', for lack of a better term, will b essential in drilling them.
He's honest, but greedy and ambitious. He won't stab us in the back, at least.
This dude. Do not underestimate him. That kindness can be quickly soured if we do him wrong. He is the best military leader of the bunch, no doubt about it. If we put him in the unexperienced legion, they'll be very well improved.
But history also seems to smile on this man. Whether that smile is of pleasure or of sadism is... up in the air.
... yeah, that seems to fairly well establish where his loyalties lie.
Fanatics need handling. We'd need someone to shore up the fact that neither he or us are military leaders.