There's something that bugs me about the rules regarding fighting two opponents. It's only the one who's alone that roll dice. That means that if there are two PC's against one NPC(more common in tRoS than in other RPG's I guess) , the NPC can outmaneuver them and it will be impossible for them to do anything about it. Very annoying for the players.
Any suggestions on how to change that?

In the last few sessions, I've let the loner(PC or NPC) choose which one to attack and which one to outmaneuver. Then the loner and the "flanker" roll a contested Move roll.

If you really wanted to involve the whole constested thing, I'd drop the terrain price and go with the move contest, like you're doing. The terrain prices are what they are to account for all the guys moving around.

Another option--one I actually really like--is that the slower guy's move acts as the Terrain TN that the loner has to make. Each additional guy adds one to the second slowest baddie's Move score. It ends up being only one roll again, but at least it makes a difference who you're running from.

Jake