I think we you are too wrapped around the force employment/force generation axle.
It may be an important distinctions in large forces but I'm not sure that it needs to apply to smaller forces.
I agree the two functions exist and I agree that they are distinct but I'm not persuaded they need separate organizations.
Since our focus is shifted back to the 1960s we might look back a bit:
1. In the old RCN the C2 system was fairly simple and robust; force employment and force generation were both managed, through a single organization, by the CNS in Ottawa. There were, in the regular force, one recruit school, one officer training centre, two big professional and trades training schools, two dockyards, two main supporting bases, sundry 'systems' (medical, communications, etc) and two fleets;
2. The Canadian Army was organized geographically – four regional commands – each responsible for almost everything within their boundaries, including schools and combat units. A single commander generated forces for the entire army and employed the combat forces in his geographic command area. There were some interesting 'overlaps:' Comd 3CIBG in Gagetown 'commanded' a R22eR battalion when it was in Gagetown on exercise; otherwise the R22eR battalion in Valcartier was owned by Comd Eastern Command. The exception was Comd Canadian Army Europe – a BGen – who was also Comd 4CMBG; he had no force generation duties; and
3. The RCAF had separate force generation and force employment structures. Air Training Command was big and important: it had many stations, schools and flying squadrons.
The three systems all made sense, all had been 'tested' in big and small wars, and all worked well enough.
I, personally, would like to see a fairly 'pure' unified command structure:
1. Four geographic joint commands: Pacific, Western, Eastern and Atlantic with a separate JHQ and Signal Unit lodged in one of the command areas – ready and able to deploy on fairly short notice anywhere in the world to command an expeditionary force. Each joint commander would both generate forces and employ them on domestic operations;
2. A few, a very few, NDHQ controlled units, groups and agencies if Ottawa is convinced that a geographic commander cannot or should not have cross boundary responsibilities; and
3. A big, integrated NDHQ (in Shilo, which is near the middle of the country?) with a joint staff to manage all operations – expeditionary and domestic.
But, I expect that everyone (except, maybe, the RCN) would object and, having lived through the destruction of our joint experiment (AKA the creation of Air Command) I do not have confidence in Ottawa's ability to create a simple, robust C2 structure. Thus I propose a couple of big, joint combat commands (Maritime and Mobile Commands) and one or two single service specified commands (Air Operations Command) for force employment and all the rest for force generation – probably with some sort of (wasteful) geographic sub-structure to create more vacancies for over-ranked, under-worked GOFOs.
I see the service chiefs as being staff officers – pure and simple – with responsibilities, as I said, for doctrine, individual training standards and equipment requirements. But those responsibilities, especially for doctrine, make them, dfe facto, the professional heads of their respective services.