Last week there were a few of the of the youth in the nets next to us. I'd taken a few bats with me to try out so I lent them out to them. They're all around the age/height you mentioned.
The three bats were a blank Hunts in a type of Scat profile 2,9 , Laver Ultra 2,10 and the Chase special sale which I'd say is a ST profile at 2,11 . I'd checked and the balls the were using weren't rocks, the Laver is a cheap one I picked up from here a while back and they lads were working on their game so they weren't going to smash every yorker.
End result, the heaviest bat with the lowest profile came out on top. Not a scientific test and one of the first team uses a Chase but they got used to the weight and the pickup in no time.