staggered setup tolerances

[omodos]

Hi all, looking at different tire options and want to know what tolerances are with tire setup, is the main thing the diameter and fitments to the rim being ok?currently run 255/50 r19 9J and 385/45 r19 10J

been told that I can go for the below no problem

275/45 r19 8.5-10.5" all round

OR

FRONT
265/50R19 (rim width range7.5-9.5")

REAR
295/45R19 (rim width range 9.5-11")