OK Squad Support Weapon and TAG (Light) are both TM pg. 270, please note that I am only using TAG (Light) as an example for a system that doesn't give increased benefits by mounting it on multiple suits, the question also applies to BAC3 is TacOps pg. 297 and the RISC Advanced Point Defense System from IO pg. 91.
So the question is: Can I mount this these system in a SSW and get the weight discount or is that already accounted for in their weight?