It's perfectly legal as shown as long as the other robots who's those balls 'belong' to are in contact with them (and your robot is not), or one of them is placed in the goalie zone at the start of auton.
With that said, it better be a very high confidence perfect 3 for 3 with the shots, otherwise you're really going to have egg on your face when you force your alliance to chase down all those loose balls before you can start any assist cycle scoring runs. Just saying, if you're go for it, better do it right.
