You are right that HM have little influence, you "hire for Amazon", not for any specific team.
And with the process changes in the US (and EU), candidates are now given the option of picking the team they want to join (which can be different from the interview-HM's team).
And with the process changes in the US (and EU), candidates are now given the option of picking the team they want to join (which can be different from the interview-HM's team).