Profile of Hannibal

Stug is probably more efficient but that does not make it more cost efficient nor does it make SU-76 a bad TD.

OK, i say'd it was on par in terms of price to performance with the stug. It costs less so it also performs less.

Like what more do you want form a 75f vehicle
60 max range(stug has 50)
170 max range pen(stug has 180)
3.875-4.375 s Reload(stug has 4.5-5.5 s reload)
fuel difference with mediums p4 45 and p4j 65 (stug has t34 0, sherman and cromwell 20)
fuel difference with special mediums Panther 110 (stug has t34/85 40, easy8 55, sherman-76 35, comet 95)

I don't know for me they look on par in terms of bang for buck.

Stug is more cost efficient AT.
Assuming the TTK times as written above (7 and 5 shots vs medium for SU and Stug):

Stug needs 21,5 s to kill an average Allied medium (326 MP, 103 FU), yielding 15,16 MP and 4,79 FU per second.
SU needs 33,1 s to kill OST P4 -> 10,57 MP / 3,62 FU

This gives StuG higher damage potential of +43% MP and +32% FU, while costing the same MP, +20% FU and +25% POP. This advantage still remains if you subtract 2 seconds of the SU TTK because of higher range. It equals out in the matchip against a T34 and improves vs Sherman and Cromwell.
So unless you can regularly take a long range shot, the StuG is better. Not to mention that a close range StuG is still a threat. A close range SU is probably dead because the StuG comes with way better defensive stats.

I'll say that this is a quite theoretical calculation since vehicle combat is all or nothing. But still, the StuG counters Allied resources more efficiently than the SU76.

su76 has a max range pen 170 and ost p4 has frontal of 180 that's 94.4% pen dude from a range of 60. The su76 also has a faster reload of 4.15(avg) compared to stugs 5(avg). considering the su76 is only 75 fuel. I'd say it's on par with the stug in terms bang for your buck AT power. Considering Allied Mediums are barely cost more than the stug while su76 is far cheaper than ost p4 and evn more so then okw p4.

The SU has an additional second wind down...

thanks for clearing that up. though i don't necessarily agree that a complete understanding of the targeting algorithm would be necessary to simulate things - we can always make assumptions and simplifications to get a rough idea how things line up with the in-game results and tweak accordingly. after all, your model also requires certain informed simplifications to be made, which isn't necessarily a bad thing if the results work out nicely.
anyway, i guess that wasn't really the point of my question. what i meant was pretty much what you outlined in the last sentence. if i understand this correctly the amount of hp shifting kind of simulates the degree of 'focus fire' towards single models? in this case (and assuming this is the major factor that defines the randomness of the outcome of a firefight) it would be interesting to see if the variance in a set of calculations with randomized values for hp transfer would match up with the variance in a set of in-game tests (to some extent at least). well, maybe i'm fetching things a bit too far but i thought i just put this out here nonetheless...

Maybe it is possible, but it will be amount of work and cross checking with in-game measurements quite a pain to get some real variance data (for a bigger set of matchups regarding DPS centralization and squad size). Everytime you realize that you tweak your model, you need to re-run the simulation again. It will probably be doable to find settings that mimick CoH2 behaviour, but it'll take ages.

My points for model sniping being the main factor are twofold: 1. Whenever I tried to verify my DPS calculations with in-game measurements I often tested a carbine ranger model shooting at Partisans. And this dude was surprisingly consistent in killing times despite the carbine having amount of RNG delays. He had a lot of shots though to even things out, but any slower shooting squad would have that as well. I had some other tests too that I don't remember that well anymore, but I still kept that as the bottom line. Second, we have seen for ages that we get way more variance in infantry test when we test them in cover. This also hints that it probably is more important that a model got killed instead of how the RNG rolls turn out. Is it true? I never tested it in detail, but at least this is my assumption.

Anyway, back to your actual question: The idea behind this HP shifting is rather easy. I say three grenadiers shoot at Conscript Yuri and the fourth at Conscript Ivan, Yuri will still get killed first, but it takes more time. But he does not eat all the damage alone anymore. The DPS dropoff due to the loss of Yuri is delayed, because Ivan takes some of the damage. This is functionally similat to Ivan shifting some of his HP to Yuri, thereby prolonging the overall time that a higher DPS of the Soviet squad can be maintained.
The way you set this up is fully arbitrary. Does Ivan give 20% of his HP? 50%? 90%? We don't know. In the game I have seen my Rifles running back with 5 models and what must have been no more than 5 HP judging by the health bar. On the other hand I sometimes drop models one by one. What is the middle ground between those? No idea. I think out of pure luck I found some settings that are "good enough" to align roughly with what I tested. We can surely find better ones down the line, but I assume they might be okay as a starting point.
The amount of shifting can be tested. There probably are multiple setups of this shifting that yield similar results. I just checked my current setup, Conscripts here get about 20% better when shifting is allowed, Grens about 10%. This can be either personal bias in my manual setup, but to some extend it makes sense in my eyes (Conscripts "offer" more targets, so damage is more likely to be spread. Grenadiers also centralize more DPS, so they shift HP to models that have comparatively little contribution to the overall damage. Therefore, power does not increase as much).

It wouldn't be an issue if they didn't come out by the time medium tanks do
Rushing a KV-8 against an OST player is catastrophic because Stugs aren't reliable counters to it. You are supposed to face the healthpool and armor of a Panther way BEFORE the Panther can arrive and it so just happens that this tank hard counters anti tank guns AND has a main gun with penetration equivalent (and superior at close range) to normal mediums

Are you talking about the KV8 or KV1?

It would have been better imo if command PIV used vCoH like hull down or like KV-2 siege equivalent, becomming immobile but maybe increasing radius of aura and RoF.

Or its general power should be boosted a bit, because while it provides buffs and abilities its perfomance on its own is mediocre at best and considering it has to be in pottentual combat zones always kinda makes it a bit lacklaster.

UKF command vehicle on the other hand while being less potent mobility and ROF vise still retain full combat capabilities, so there is no reason why combat PIV cant be at least on Ostwind lvl of AI capabilities.

The CP4 has the same AI capabilities as the normal P4, it just does not have much AT.
The British command vehicle ability more than halves all capabilities. Double the reload for all weapons, which approximately halves the DPS against tanks (not including the accuracy nerf). The CD, reload and accuracy modifiers lead to an about 70% nerf to all MGs at all ranges on a Cromwell. I don't know what you mean by "full combat capabilities". Alpha damage yes, but there will not be a great follow up.

I'd say the bonuses of the UKF version are also better, but overall I'd still take the CP4 over a British Cromwell version. The only thing saving that ability is that you can put it on a surviving AEC.