I just found your query for the players with multiple listings of the same national team. I'm happy to help out (I only recently got around to creating an account, but have been doing anonymous updates for some time now).
Part of the problem I think that causes these is different sources define the start time or year for a player in terms of being on the national team differently. Fot example, is there a consensus on the site here for when
- a player is first on a game roster for a team in say 2017 but never comes off the bench
- that player then actually appears in a game for the national team for the first time in 2018.
Is their start date on the national team 2017 or 2018 ?