It is not going to accomplish what you are looking to do. It will not hurt anything as long as the cables are connected properly but the voltage output of one charger will fake out the other to think the batteries do not need charging and it will decrease the charging of that charger.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7