A couple points I don't know I agree with...
-Trooper Designation... I see your point Brad, but while I think it's applicable and "generic", I still think that a Clone Army would have a substantially less diverse ranking for "troopers". I think Sergeant is a leaping point for rising through the ranks, but that anything below Sergeant is "Trooper". I could see at the same time "Trooper 1st Class" or some such, but I think Corporals and Privates are non-existant ranks within the Clone military... To me, the Clones come out as skilled soldiers. More skilled perhaps than even recruits would come out of training as, and thus they're treated differently... How that plays out with the Imperial military (which I view as recruits), I don't know. I could see Corporals and Privates and PFC's and such. I don't know. Just how I view it though. I see a simplification as being something the Clone military would have adopted at least.
-On the Pauldron Issue... To me, the pauldron works a dual role. First it serves as a means for civilian interaction on some level... Who they can talk to, who they can't talk to, etc... I think that makes some sense if Stormies are doing a policing role at all. But also I think that a HUD system is something prone to failure, or something that isn't reliable in combat situations. The Pauldrons don't indicate specific ranks but rather a generalization... Orange being the "highest" color indicating an officer on the field but it could be anything from a lowly Lieutenant to whatever the highest rank is that dons the armor (not sure on Generals from my own POV but I could see Captains at least being the highest ranking Stormtrooper Officers). The colors make the fog of war clear up a little bit, and you can see where your sergeant is, or your specialists... The Pauldrons aren't always used, and often it's more the environment that dictates their use rather than anything. Tatooine's sandstorms and such give good reason to use them there, and a planet prone to fog for instance, or rain/snow (though not a frigid world like Hoth, just a battlezone seeing snow flurries or whatnot) would make sense to have the easily identifiable Pauldron. I figure Corpsmen, if they exist, use them too... I have this concept of them having their own pauldron with a striped design. I even actually thought of doing a custom Stormie Corpsman with a red/white stripped AT-TE Gunner's Pauldron. Just a weird idea I had that I thought would look cool (I figured you'd appreciate that Brad).
-The Issue of "Field Commanders"... I don't look at them as being as high ranking as a general in Earth Military terms... To me, I'd liken them more to an "active" Colonel perhaps. I view the Jedi as clearly above the Clone in rank, and as the true General on the field... The strategist. It's the Clone's responsibility to coordinate that strategy on the field then, so I view them as a bit lower rank than General but not terribly lower.
I do see them as being active soldiers on the field too, more than others, but even the Jedi are generally active in battle... Which is odd and unique to Star Wars but it's how I just view Cody and others. Bacara was at the front, Cody was at a place where blasts were zinging past so I viewed his position as more of a frontline Commander because of that... Gree I could see being similar but standing with Yoda because maybe that's what Yoda wanted him to do? Otherwise though, my view of CLone Commanders is that they're active fighters too... Probably better protected and surrounded by "better" soldiers than just "Troopers" (Lieutenants, Captains, Sergeants, etc.), and not AS active in the fighting as any random grunt, but I view them as definitely active fighters...
I then view military structure of the Republic as having a SUBSTANTIAL Sentient grouping. Strategists like a young Jan Dodonna for instance, a young Wilhuff Tarkin, etc., etc... And sentient soldiers. Maybe doing mop-up work, acting as support and such for fighter crews, crewman for destroyers and such... I think the republic military was "small" (for a galactic military anyway) prior to AOTC, but it would swell during the Clone Wars and while Clones would make up the main fighting bodies that there would be substantial sentient support military personnel and some fighting bodies too.
Just some more random thoughts... Fun turning a rather pointless topic into something tollerable.