I use 2 LEDs as side lighting & a 600w mh overhead in my flower room which works great. Be sure you've got a vent to pull out the heat especially if in a small space. No reason you couldn't use the same led/mh combo for veg but it could be overkill if temps are high after venting with an exhaust fan in which case just use one or the other. You'll likely get fast vegging with that setup if you can keep it nice & cool in there.