You have two different strains in there so they'll respond differently to the same stimuli... Even the different plants of the same strain will grow differently. Best bet is to move them around the tent, if you can. Same with the fans if possibleee. If I have differences in the same space, as I do in my grow right now, I'll put the shorter plants on a plinth of some kind and raise the whole lighting system. If you can get multiple hygrometers that will be a good shout, so you can see if there are any differences in temp and humidity in specific areas of your tent. Good luck!