The doctrinally pure amung us (are there any?) will be aware that CAS is dead, long live CIFS (Close In Fire Support).
I am sure that the rear seater has enough to do flying the aircraft on the NVS in and around trees/wires while slaving the gun to provide local protection from small arms/manpads. Your having a laugh if you thing he is also going to call in Fast Air. In addition, the front seater is the chap with control of the sight (TADS) and he is only one who can operate the LASER. I expect the 50% figure will be more than enough if achieved.