If this is in a command unit, all the more reason to separate them and not combine them. Having worked in all kinds of command units, the ones I hated the most were the ones that either had one speaker for everything, or the ones that put all the speakers in one spot.
I'm working as the dispatcher/RADO and I have my head down writing or filling out a form, or looking at my computer screen and someone calls me. If they did not identify which channel they were on, and all the speakers were in one spot, how will I know what channel they are on? If the speakers were separated, and labeled, I know just from which speaker they came from what channel they were on. I understand about desk space, I've seen some behind the computer monitors, and others in the ceiling. But at least they were separated.
Hope this viewpoint helps,
Onelick