Hi to all,
It is quite common at the company i work for , and i don`t see any problem about it.
Regarding the law ,there most be a capt so the senior one is the one(no big deal being the #2 because you are also a capt).
Regarding operation of the aircraft while on rhs one must be a training capt to fly if not fly it on lhs(2 mature capts can work that out just fine).
Best of luck to you all