RE the piano arrangements comment, there is an interview with Split Enz from a 1981 Aust Playboy or Penthouse where Eddie actually says that a lot of people believe that Tim writes the piano parts because he writes the songs. Not true at all, Eddie politely but firmly explained. He writes the parts and he felt that his contribution was equal to that of the Finns and that if he didn't he wouldn't be in the band.
Having said that, I'm curious as to what Eddie's contribution was to I Got You. Right or wrong, I get the feeling that Neil didn't present the song to the band with the D to E musical bridge after the second chorus. It just sounds like an Eddie piece to me.
I think one of the Beatles' first songs gave credit to George Harrison as a co-writer and Paul later said that it was because he wrote the solo. But he was amused that two naive teenagers did that cos, as Camus mentions, it's not the norm for song-writing credits to be given for writing a solo.