I would say that HOI is much more a "war game" then SR is... but here in lies the problem. HOI has built upon itself through its releases, and is actually a much better "war game" then SR (even if all the ideas we all have were implemented). But that is what you have to do to become a really big, you have to focus on 1 thing first and do that really really well. Then you expand.
SR seems to have taken the other approach where they try to incorporate as much as possible, but nothing works amazing.
Lets take for example HOI3 HQ and ordering system. I can put individual armies or go as high as Theater commanders on AI control and give them specific province targets I want captured. Examples would be I want leningrad, Moscow, Stalingrad all captured. The AI will automatically move units around, order planes and bombings, respond to counter attacks, support attacks to defeat units and then move units to other places. WHILE it doesn't do this perfectly, it does it quite well. You can even give targets to your allies as the Leader of your alliance. Germany can give targets to Japan to prioritize targets in China, targets for Italy in the Mediterranean, Hungary, Romania, Bulgaria against USSR, etc, etc.
The only pain of this entire system is the actual manually putting all groups into each HQ.
Or lets take the convoy system, it works exactly the way its supposed to, and is quite annoying how damaging it is to your economy. As Germany it is quite easy to complete destroy Great Britain without ever having to land troops on the mainland. If you build nothing but submarines as your navy, this means you can focus all your research on Land and airforce, and only on submarines and sub doctrines. You submarine force now assuming you have been building 5-10 per run in the range of 50+ by 1939, and your subs completely decimate all convoys from the British. Britain suffers the same fundamental flaw that Japan does, all resources are built in its colonies, and if you destroy the convoy system, Britain cannot even build fast enough to replenish the losses, and all remaining IC (around 50-80) is completely set to building convoys and escorts.
If Britain cannot get supplies to its troops, their org and strength falls, which means Italy can take Malta, Gibraltar, Suez canal, etc and further cut off Britain's supplies.
And with Britain now only to produce at around 40% of its full production, and all production now going to new convoys and escorts, your naval bombers and subs, and Navy are now able to fully wreck havoc on Britains Navy because they will not have the IC to bring new ships into service or repair them. Now as Germany in full war mode you are outproducing Great britain by around 6-10 times in Industry output and can focus all your research, manpower, and production on the future war with USSR.
What makes this a "great war game" is that its very realistic, and very balanced, to the point that if you really want to win you have to research WW2 and what nations did right and wrong. But they have also focused completely on the war aspect. Only once they got that right did they start adding in the ideas that you guys are wanting in SR. Funding Partisans, Partisan underground networks, etc etc. And now with release #4 coming out in 1 year they will further develop the war game even more and build out a few more of the other stuff.
From my perspective, SR is not a war game, not even a "4X" game. It's an economic game with war added. You have to learn what it takes to run a war economy, to plan out the next few years of what your going to need to build what your war is going to need. You can't simply play this game and arbitrarily build whatever you want. That is what SR needs to focus on and build out, which is where all my suggestions have gone.
Upgrade buildings, repair buildings, Infrastructure, Upgrading units, scrapping units. All of that goes back to Production and economy, and if all of that was easy, intuitive, and amazing then I think they would easily compete with HOI.
I think that Loyalty plays an important role in this, but I don't think its a very high priority to the point it needs to be changed before launch. However, I disagree with the current loyalty mechanics completely, and would love to see them changed. Do we really believe that Germany conquering Russia, that they would really get 66% of the materials? Ha the Germans hated the Russians and were exterminating them. USSR lost approximately 20 million people during the 3 years it was at war with Germany.