,Yes exactly if they are in supply they have what they need.
Once you come around to the idea that supply check = suffiecient fuel you will undergo a relaxing euphoria and not be so stressed, about perceptions as to what the game is simulating and what isn't simulating, at the end of the day there seem to be mechanics to achieve the playing experience of not having not enough stuff to do what you may want to.
Then it might be a good idea to think what things in game that you can do to disrupt how many things an enemy can keep operational within what you said was a Stacking Limit, as this seems to be strategic areas. Then it seems to me as players that we have the information and if we build the right things, the tools to have some impact on logistics effects in game. This is quite an improvement on Hoi 3 in my view.
Lets say Italy and Germany put forces into North Africa, I pummel their convoys, with submarines and aircraft from Malta, with no remorse I bomb their rail heads and ports, and thus degrade their Supply / "Stacking Limit", and then roll them up with my 8th army. Will Hoi IV let me do this, with a logistics cause and effect, that I can understand? I hope so. If it achieves this end not so bothered if Supply Check is aggregated to mean ammunition, fuel, horse shoes or wooly socks.
Apologies for spelling errors.
All good, didn't notice any spelling errors

. Also, I'm not 'stressed' per se (it's a game - I'm interested and enthusiastic, and I'll argue a point vigorously, but the last game that caused me any stress in the traditional sense was Dark Souls

), I accept what the system does and what it doesn't - and I'm definitely not trying to have a go at you or anyone else

.
As you say, we can hit their supply operationally - the issue for me is that the strategic impact has been warped somewhat by the approach that's been taken. If, for example, the Japanese Navy is based on the Home Islands (or the RN in the UK), and haven't decided to all base themselves at a small fishing village, they'll never, ever, ever run out of capacity to operate strategically. The US can bomb the port and reduce it's capacity (hit them operationally), but the fact that US submarines are sinking all the oil convoys from the Dutch East Indies, or U-boats are sending all the convoys crossing the Atlantic to the bottom, won't mean anything strategically for the operating potential of the Japanese or British fleet stationed at home.
That's the kind of strategic distortion I'm talking about, and the new supply system can't deal with this at all - HoI3's system, while poor, at least had the cogs in place to influence this situation, even if the base game didn't do it terribly well.
I've got no issue with people preferring a strategically simpler approach, but I also think preferring a more historically plausible strategically approach isn't a bad thing either

. Of course, I absolutely respect the devs right to make the game they want to make, and I'm not saying they've made a bad decision from a game design perspective, just a historically implausible one.