In all my hundreds of hours into HoIIV Old Guard commanders always were a dead asset to me. Not a single time I used generals, admirals and Field Marshals with Old Guard trait. I just can't see any reason to. In all my Multiplayer games I never encountered anyone who used them.
With Generals - there's already a lot of generals without this trait and even without it a bit of political power can get you a general who will level up fast enough to outperform Old Guards.
In case of FMs it is even more important because they already level up super slow and with Old Guard penalty things become much worse.
Only time I used them is when I assemble a horde of cav+mp divisions to carpet garrison some territory, so FM can have 24+ diviions, without facing any combat.
Why would you use them? What are the reasons to assign Old Guard commanders when you have plenty of normal commanders? What role they fulfill if they see no use at all?
France starts with three Old Guard Field Marshals with Defensive Doctrine and no other field marshals, thus you're kinda stuck with one. Usually I put one on 'garrison command' duty as with '39 engineers when I'm using Grand Battleplan that combination gives troops under their command a 59.6% entrenchment bonus, thus all my garrison troops sitting in ports all over the world will get that bonus. For fronts I'll often have another with command of the infantry and other defensive troops over the entire front without their plan activated so they'll move up and fill in any gaps created by my mobile troops and marines/mountaineers who are on the offensive. Doing it this way they almost never pick up a point, as their troops seldom attack and they don't get much experience from their troops just taking defensive fire and if my offensive is working there's not much of that going on anyways so they're mainly just moving into place. Often at the end of the war they'd only be at 14% or so progress to their next level.
Once however I gave Georges, (a '3' with defensive doctrine) command of the Spanish Republican army when they offered it as an expeditionary force. He was holding the line with a handful of mountain troops in the Alps while I sent most everything else at Germany and didn't need the distraction of the Italian Front. They had a plan in place but I didn't intend to activate it until I could get another dozen mountain troops over there (and Tassigny who'd picked up a the rough terrain medals in Spain earlier but was currently in the Austrian Alps) and while the Spanish Republican Army was numerous, it was back when the AI had real trouble building effective divisions so they were mostly crap, a lot of three battalion International Brigadiers mixed in with some six battalion regular Infantry with maybe engineers and support art, I can't recall. I went back to the German front which had become especially diverting as the Soviets had declared and I knew when the Germans had been taken care of that I'd have to fight the Soviets over Iran/Iraq/Afghanistan shortly afterward so I wanted to get as much German production as I could and to beat the Bear to the Polish border (at least). Captivated by that little race I forgot all about the Italian Front.
The next time I looked down Georges was sitting at the toe of the boot as a '6' and had picked up one extra medal and almost gotten another few. I must have pushed that button without realizing it at some point when checking up before I forgot all about them. Who knows just how many Spanish Republicans died getting him that medal and levels, but there were about seventy divisions of them all told and thankfully it was after they stopped having expeditionary forces drain your manpower pool. Downright amazed that could happen, both an Old Guard Field Marshall could gain that many levels so relatively quickly and that the Spanish Republican army could take Italy with only a cadre of maybe ten mountaineers bolstering them, I gave them the honor of liberating Denmark which I had bypassed trying to make as much progress east before the Reich capitulated.
Boom, next time I looked back there he was now a seven and had finished one or two more medals and was close to the rest. One was definitely 'Logistic Wizard' as I'd been less than diligent in ensuring their supply taking the attitude 'suck it up boys, Field Marshal needs another medal and Russia is going to go worse without it.' I'd decided I'd let Georges be the one to command the troops headed to Moscow, I'd never realized Old Guard Field Marshals could gain levels that quickly, or any Field Marshals at all for that matter, I seldom let them command 84 or so divisions on offensives which is what those ten or so mountaineers with the Spanish Republican Army amounted to.
Georges got to Moscow and eventually the Urals commanding everything I had on the Eastern Front and ended up a nine with all the medals he'd made any progress on, I don't think he could have gotten any higher. After telling the capitulated Soviets 'The Bonapartes send their regards' I realized that Georges had become the most effective Field Marshal possible, something you can't do without that Old Guard distinction as it can't be picked up and once you get to level nine it's just another (minor) bonus, it no longer is any type of penalty.
On the other hand in a recent Soviet game the Russian non-Old Guard Field Marshal I promoted from a level one general (Max something) made it to level eight in about three months of fighting on the Western front and would have made nine in very little time had the Germans lasted longer, so there is that too.
