Haven't got the 737-8 FCTM in front of me but pretty sure it reckons Auto 1 should be adequate for most ops, don't think it goes further but assumes at least some, maybe even most, of the pilots may have some logic and brain functions!
Was never a fan of autobrake on the classic but gotta admit on the -800 auto 2 and reverse on touchdown does a very nice job when I want to make a highspeed for whatever reason.
Getting rid of the autobrake (smoothly) still a work in progress.
Cheers
galdian