Gantry with mismatched lead screw pitch

I want to make a plasma table using some ball screws and linear bearings that a friend got from an equipment recycler who works next to him. I have two lead screw/ linear bearings with 4 foot travel and one with just over 7 feet of travel. I would like to make a gantry setup with the gantry moving on the short 4 foot axis and moving the tool along the gantry using the 7 foot lead screw and bearing.

The screws I would like to use to move each side of the gantry have different thread pitches with one having a 5mm pitch and the other at 6mm. I think I understand that the way I will configure the linuxcnc software will treat each joint seperately so I can compensate for the mismatch in the configuration. Is this something I could configure around? Would I be better to rig up some sort of a correcting pulley?

Thank you

Josh