This is just my opinion, and am just tossing out a suggestion.
The way i always looked at it was if i did back on both press days (bench and overhead), then i could get twice as much back work as opposed to just hitting my back once a week. After i bench, i like to hit a set of Kroc Rows for 20-30, and after i overhead press, i like to 5x10 DB rows.
I also do pull-ups on both days. Wendler recommends doing 2 pulls for every 1 push, and this is the only way i can get in that much pulling. If i squeezed that many pull movements into one day, i dont think i could work at a high enough % throughout.