I planted it in a mix last year with buckwheat, cowpeas and sunflowers. Was a heavily used summer plot before a fall planting.
I believe I used 15 lbs/acre Buckwheat, 30 lbs IC cowpeas, 15 lbs lablab, 5 lbs sunflowers. We didn't have anything resembling drought conditions however. The lablab seed is comparatively pretty large so make sure you cover it properly when planting.