I would expect that the man who travels and returns (as a pattern) is entitled to his seat. The newcomer has been ‘squatting’ but has no permanent claim on the seat.m
In my experience, most shuls that sell tickets offer seats first to the person who bought them the previous year.
Our shul has brass nameplates on the seatbacks for those who have purchased permanent seats. We don’t sell tickets for the holidays, seats come with membership dues.