Nicky Wu is 40 and Kevin Cheng is 41. So looks like Tangren is adhering more to history than "Gong".
There's going to be quite a bit of emphasis on brotherhood (like Young Warriors and LOCH2008). 4th and 14th Prince are born from the same mother. 13th Prince's real mother died young, so he was brought up by 4th/14th's mother. 4th and 14th are full-blooded brothers but they become sworn enemies. 13th and 14th grew up together like twins, but 13th chose to be loyal to 4th. So BBJX will be loaded with themes of brotherhood loyalty + betrayal. Much less emphasis on love and romance than "Gong".