I have laid down a few Player support modules such as CAS, transport and Artillery.

Using RHS with the US Army Artillery, when I go into my mission, the Military AI commander takes control of my three arty units. They show up on the support tablet, but no option to use them. Then while watching they fire, assuming from the AI Commander?

The module isn’t synced to anything except the Combat support module. CAS and Transport helo work flawlessly

If you're running an AI mod like VCOM make sure it's turned off on all the crews.

ASR AI does that aswell. Ive stopped using VCOM until the resource hog issue is fixed. Also the reason why you can't use them is because RHS artillery isn't supported by Alive. CUP artillery works well and of course vanilla vehicles