Your second scenario does work: he can transfer mid-year, and be eligible to compete one year after his transfer. In most circumstances, the NCAA by rule would allow him to receive a scholarship immediately upon transferring, although that is highly unlikely to happen. It is not very likely that he would be awarded athletic money by school B at any time, simply because school B won't believe they need to.
And my additional question to this is purely out of curiosity. If he chooses the above, is he allowed to participate in any and all team activities in the fall? So, suppose he xfer's after the current fall 2015 semester and enrolls in DI School B immediately (spring 2016). Based on your description above, he would be eligible to play for DI School B in spring 2017. Would he be able to participate in all of the fall 2016 official team workouts?