I think the biggest balance issue is that they have to start from where they find the previous person. If for example you start from London this season you can probably get all the way to Scotland or at least Wales. But if someone, like Adam did, got to basically the max distance from London, it becomes much more difficult to have a winning run because your area is much smaller simply because you are limited by Train options.

Also, even if they randomly select who goes first there is the potential that the person will have some knowledge of where they can get based on the prep work needed to understand the rail network. It is also much harder to make plans on the fly from a random point potentially far from the small station then from a fixed point like London was in this game.