With Respect Gunny - but how do you think we got to the structure before the current one (I am honestly not sure what the current one is, or if we have one)?
The structure before the current one (integral mors, pnrs, anti-tank, recce, snipers, logistics, transport, etc) were all based on accomodating the technology of the day, including comms and logistics, to the needs of the battlefield of the day.
The Canadian Army fought three campaigns of note: the static one of WW1 with lousy comms; a more mobile one in WW2, of short duration; a repeat of WW1 in Korea with better comms.
Capabilities were held internally because once the balloon went up nobody could hear a thing, and just drove forward, or held on, until they couldn't any longer. Every battalion, coy and platoon was fighting its own personal little war. The guns were the play things of the Brigadiers and Higher. As was the Air Force. The more internal capabilities held at the lowest level then the longer the entity could fight and influence the battlefield.
I see Bruce's Schiltrons, Wellington's Squares, the Kaiser's Pillboxes, the Cold War's Defended Localities ("No Lads, you are not cut off, isolated and surrounded, you hold a strategically significant and tactically effective position in the enemy's rear) and Minefields in much the same light.
Bruce packed a few hundred men with sharp sticks into hedgehogs that he used to breakup the battle field into smaller fields and reducing the enemy's ability to manouevre. Then his reserve could take the enemy apart in detail. Wellington's squares did the same thing allowing his guns and cavalry to concentrate on a series of isolated threats. The same for the pillboxes, the Defended Localilities and mines.
You don't expect that every step the enemy takes will cause him to stand on a new mine. You expect that the presence of the mines will slow the enemy, break his cohesion, channel his forces into killing grounds and break his advance up into killable packets.
I could take 1000 men from a 4000 man brigade and give them Mel Gibson's tree trunks, Wellington's Brown Besses, or the CEF's Ross's and have virtually the same force.
Or I could take the same 1000 men, leave 100 back at depot, put 100 into comms and log, and field 4 coys of 200 - split into 4 platoons capable of independent action.
Or I could take the same 1000 men and convert some into an organic arty platoon (mors), an organic engineer platoon (pnrs), an organic cavalry platoon (recce), and an anti-tank platoon (and we can continue the debate if they are gunner wannabes or cavalry wannabes).
I don't disagree with your notion of reverting to status quo ante 1917 and holding Infantry, Gunners, Engineers, Cavalry, separately.
I do argue that Mel Gibson's tree trunks can be effectively replaced with timberwolfs, CG-84s, Javelins, GPMGs, HMGs, GMGs, and even "light" mors (60 or 81mm) and thus create a "mine" with a 2 km range band / area of influence. I also argue that 1000 PYs could translate into 20 to 40 of those "mines" and still leave a Brigade commander with 3000 PYs to find gunners, mech/mounted/ armd/cav, engineers and support.