I'd prefer chest-back-shoulders and arms-legs then
1-chest back shoulders
2-off
3-legs and arms
4-off
5-chest back shoulders
6-legs and arms
7-off
like this ? don't you think that is a little overlap for the arms ?
what you guys think that is the best split when training each bodypart 2x per week, and could only train 4 days per week
cheers