Different landing distance with/without rev thrust

[extricate]

Hi,

This is a performance question. I've looked up FCOM 1 for the different landing distance based on landing with/without reverse thrust.

My thought is the rate of deceleration after landing is the same with or without reverse thrust with the use of Autobrakes.

If so, why does FCOM directs me to add an adjustment to the landing distance with autobrake 1, No Reverser on a dry runway and also on a Good Braking Action runway with varying autobrakes settings with No Reverser? The rate of deceleration should be the same and if so, shouldn't the landing distance be the same too?

Thanks for the enlightenment.