Airbum makes an important point, for turbojet dispatch 121 requires that landing weight allows a full stop within 60% of available runway (121.195 & 197).
Once airborne the only "requirement" is that you can get it stopped in the length of the pavement.
At all four of the 121 carriers where I've worked, runway analysis tables were used for dispatch and AFM landing distance tables were used for airborne reference. The runway analysis tables are typically generated by a third-party, but are based on manufacturer's data.
121 dispatch landing weight requirements are essentially based on a 50' threshold crossing height, ie: glideslope (121.195-197). Part 25 transport category airworthiness standards also dictate that landing distance data is based on landing from "a point 50 feet above the landing surface" (25.125). So, as far as I know, all of the manufacturer's data would essentially be based on landing "beyond glide slope" as your airline puts it. I'd be curious to know more about your tables, sounds like custom info that your company has requested or generated--though it would have to be based on manufacturer's data. Very interesting.