two star + 2 one star spaces plus the Staffs. In peacetime -- and the US Army has been at peace since 1945 -- flags and spaces mean more than capability and competence.That's why when we ostensibly went 'modular' we deliberately did not restructure the EAD echelons to cope with that 'modularity.'

The Div Cdrs insist on TACON of CSS elms in their AO because they want control of all forces in an AO if they're going to be held responsible for that AO. That is simply perfectly logical self protection in an Army that, at this time, hates decentralized execution and where few trust people they do not know -- a factor stems partly from mediocre training and partly from institutional bias....

Span of control depends little on the technology or communications ability available; those factors are a crutch to allow marginally competent commands / commanders to function with an enhanced degree of success. The tech stuff can be a force multiplier but there are absolutely no guarantees that it will be.

The effective span of control really rests on state of training or experience at all levels AND ability plus willingness of the Commander(s) to delegate and trust their subordinates. Really good units / people can do a span of 9 or 10, really poor units / people have trouble with 2. An average of 3 to 5, mission dependent, is a rule of thumb, -- and thus a design parameter -- and little more. It very much depends on people and that level of training or experience...

If you recruit, train, promote and retain your entire force for great competence you can design small elements with a large (~10) span of control. If you do the same things to achieve mass and thus aim for acceptable competence, you can got to a span of ~5. If you're in need of greater mass, you'll have to accept less competence and may be constrained to a span of two or three.

Since people change with time and the Peter Principle exists, there is little chance of ensuring an acceptable design size of the span for other than a year or two at a time. Any attempt to design for specific people and mission s will probably have to change when the parameters change; thus the need for a simple, generic organizational template / TOE that allows then current Commanders to tailor their forces for specific missions with little effort. If that is done reasonably well, then the span of control issue sorts itself out with no problems and you may well have a Bn commanding a 300 plus man Co Team; seven independent Platoon Task Forces and have two Co Cdrs assigned to CP guard along with their Hq elms.