Yes, I've heard of C/L combat, although it's many, many years since I've seen it.
If you want something free, you could look at dxf2gcode. I used it for a while before buying Vectric vCarve. However, there is one thing to watch. CAM applications often generate gcode which allows for tool diameter and the gcode contains the actual toolpath. When you use dxf2gcode, you specify for each cut whether you want to cut on the line, or to left or right - but not by how much. I don't know how it works in Mach3 but in LinuxCNC you have a tool table which defines tool diameter (and other things). LinuxCNC then uses info in the gcode file plus tool diameter to calculate the toolpath on the fly. One useful side effect is that you can allow for variation in cutter size without regenerating the gcode. I'm sure that it would work in Mach3 as well, I just don't know the details.