Satellite imagery tiling problem across a landscape

I’m sure I’m just missing something simple here, but I cannot seem to get my material, which uses 4 satellite photos to span in a 1 to 1 ratio over my landscape. I have tried using Landscape Layer Coords but can’t seem to get that to effect anything.
Does anyone out there know what I’m doing wrong? Thanks in advance!6c0746216e574dc7e8643d30ef69e3bbf72c4537.jpeg