Well, not necessarily, I would just try to make it sound evenly weighted in total. Cellos can still be to the right but the heavy bass would come from a synth and I would want that in the middle. The bassoons would collect dust in the basement. 
I would also use a stereo imaging tool to make sure the low frequencies are centered. In your track the bass is the only thing down there so it feels like the mix is leaning to the right.