at three words a minute (Hey, I'm old and never learned to type, takes longer with one or two fingers...), I submit this better late than never compost. Er, composition...

The 'E' designations below are Enlisted Pay Grades, 1 being the lowest, 9 the highest. Here are a couple of charts: LINK, LINK.

In the US, Marine LCpl (E3) and Army Spc [Specialist] (an E4) are effectively senior privates, normally not in leadership positions -- though the good ones become de facto leaders or 'acting' leaders on occasion. Marine Corporals are Team (4 man) Leaders and Sergeants (E5) are Squad (13 man) Leaders. The US Army does not use generally use the rank of Corporal and uses Sergeants(E5) as Team (4 man) leaders while Staff Sergeants (E6) are Squad (9 man)Leaders. A Marine Platoon has three rifle squads and a small Hq element; an Army Platoon has three rifle squads , a Weapons Squad with assigned or organic MG and ATGW as well as the small HQ element.

Note the Marines have lower rank leading more people. Or the Army rewards leaders with more pay...

In peacetime, Team Leaders in both services will normally have about three to five years service, Squad Leaders four to eight. In wartime, those periods will be less and will vary considerably depending on many factors. Marine Platoon Sergeants are as 82Redleg noted while Army Platoon Sergeants are by TOE, E7s and that rank is hit at about 10-15 years in peace time and only slightly more rapidly in war time. Obviously, persons one or even two ranks below the TOE or normal rank are sometimes leading units and often, Platoon Sergeants are acting Platoon Leaders in the absence of an Officer -- as a Platoon Sergeant for almost seven years, I spent about five of them as an Acting Platoon Leader in three different Battalions on three continents in war and peace.

I even ran across an Artillery Battery in Viet Nam that had a SGT (E5) as First Sergeant (Co Sgt Maj), normally an E8 position. The Kid was doing a good job, too. To top that off he was not a long service NCO but a graduate of the NCO Candidate Course, a Viet Nam era 90-day school to convert likely Privates to Sergeants to replace the high losses in NCOs in Viet Nam. Not present today.

A part of the problem is that our promotion system in all services must, by Congressionally written laws and pressure be totally 'fair.' As you can envision, that forces mediocrity.

It is also my opinion that our training is, while better than it has ever been, still sub-par in many respects. We try to cram too much in too short a period to "save money." As usual, penny wise - pound foolish...

That training shortfall is most apparent with initial entry people, officer and enlisted but it also applies to NCO training. That, too is better but it's still not adequate and it focuses on too many things not remotely germane to combat proficiency.

While many in the US Armed Forces have fought and are today fighting, the broader Armed Forces and the Nation missed that. The Nation and the bulk of the Forces have been at peace since 1945 -- and it shows...