If the City has the first gym, and I think I can tell the official gym building in the shot we have of the island, then its definitely going to be Non-linear. The starting town is after you arrive on the island there, and the second town usually between starting towns and first gym city is all the eay on the other sode of the island, after a cave cpnnecting a route and the starting town. And then there is the fact that route 2 should be in the northeast corner of the island, meaning routes 3 and 4 are somewhere between the loop on the northeast side and leading south to the gym city respectively. So ueah, its not a straoght line exactly, offers quite a few optipns of how to travel and zigzags all over.