You don't need the retina MacBook and iPad, my bet is you won't use the iPad
Macbook is a replacement for a Surface Pro 3 - I just don't get on with it. It's my travel/meeting buddy. Main machine is a 15" rMBP.
iPad is a replacement for an Air that I use all the time, but is constantly running out of space...So Air 2 with 128Gb.
Phone...Just cos.