Leinster’s Jerry Cahir came off the bench last Saturday against La Rochelle and found himself packing down opposite French international Uini Atonio, all 145kg of him. Not bad for a 25-year-old who’d spent the previous two seasons being named player of the year at Dublin University and then Lansdowne, and was not on the radar of any provincial pathway. On the wing, Joshua Kenny scored two tries on his European debut. Six months earlier, he showed up to make numbers at pre-season training from the Ireland Sevens squad. That’s eight tries in six games for a player who joined on trial and may…