Generally, if you plant a flower or vegetable seeds you thin out the weaker seedlings. When we grow weed we expect them to be all perfect.
With the different phenos and seed viability, it is possible that they are slightly different. I have had seedlings that I was ready to pitch that actually ended up growing bigger than there sisters. Sometime the runts will end up vegging longer and get bigger. Yes, it is a little light but when it is that early I would not be that worried. You can sometimes mess up more trying to correct a problem that does not exist.