I think the 1ACC ATC experiement was tried in Iraq with fairly unsatisfactory results. Iirc, the ATC guys were limited firstly by peacetime rules which dictate where and what sort of services they can offer with what facilities. Secondly, 1ACC are involved in TST, liaison with JTACs, weapons to target matching to ensure the correct asset is sent to the appropriate situation and JTAC. This all requires familiarity with Mode 1,2 and 4, as well as 3 and C, battlespace management and Joint fires techniques (such as keypads), and data link procedures. In Iraq, they were quietly returned to the UK fairly quickly.
I'd suggest that there are few, if any ATC guys who have similar experience of those disciplines now. That is not to say that appropriate trg couldn't bring them up to speed in time. However, an environment where 30 seconds delay in sending CAS can literally cost lives is not the place to do on the job trg.
Both branches have good and bad guys. However, we should acknowledge that they are different. We can and should draw the branches closer. However, there appears to be an indecent enthusiasm by the ATC Staff Mafia to place their guys where, right now, they're not necessarily ready to go.
More haste, less (branch politics motivated) speed I would suggest is the order of the day in ATC and FC amalgamation.
Regards,
MM