Hi, i've got a 1.2mx1.2mx2m tent, and a Budmaster 4 LED lightsource.
i find that the Budmaster is slightly too small for my tent, recommended is 80x80x200cm apparently, roughly the same dimensions as your tent.
i've got 4 plants in there atm, but one has been in since late Jan and is big.
big but slow to mature, and i suspect its either light limited or by the size of my RDWC buckets.
that said, as she grows taller i've seen the biggest plant undergo light burn from growing too close to the light (had to bring the tallest branches/colas down with plant ties.
the other 3 are about 20 cm shorter and are almost ready for harvest.
I've had to raise my light to near top of the tent to accomodate the ladies, but i suppose if your plants are smallish still, the extra light would benefit them while in vegetative state.
as
Sheesh said, you'll want to keep them shortish by LST if wanting to use both lights.