Well, usually the pieces I rewrite work well, but need tuning, and tuning requires a lot fo PvP games, so it's impossible to do it in private. Bugs usually appear at connections of new and old code, hidden before from sight by how the old code operated, uncovered with new code. And I can't rewrite everything, but step by step.
This isn't about how good you are at your job. I think you do a great job and are really talented. And I and many others appreciate that you picked up the tab after the devs stopped updating the game. The thing is, you need to accept the limitations. For now, you are a 1 man team (or 2 with Denniss, even though you two do different tasks) and you don't have any testers that can help you iron out bugs. So you lack testers, time and resources (1 person doing a job that should be done by multiple). In such conditions, it is wise to not try to rewrite everything, just fine tune the important parts.
As for vehicles problem - I have clearly indicated to Denniss that according to my AIvAI tests, and in light of the new supply model, Axis player has too many vehicles in GC'41, and they should be reduced by at least 100k, possibly more. As I'm not doing any data and scenario changes, I couldn't alter it. So now it's a case of scenarios requring some tuning, not a problem of the new code. And as you said, it brings many improvements.
A fine solution. I hope he does the same for the Soviets though, otherwise we will be seeing super mechanized Soviet armies in 1943 and beyong.
And what about features like HQ support, many people don't use it as it's working so bad, those which use it report many issues it has. Automatically it's something I would like to rework, even if that means a few patches will be needed to iron some bugs (less so than in case of supply, as more refined problems with supply or retreats tend to appear after many turns and only in specific cases, whereas SU reassignment is a single static segment of logistics phase, and can be easily tested, also in AIvAI games).
This is exactly what is wrong here morvael. I have the feeling that you are losing focus on the big picture and starting to tinker with things that don't matter whatsoever. AI HQ Support is maybe used by 10 players from the whole playerbase. It is a broken feature but it doesn't need any fixes because it is so damn unimportant that no one cares. And there is a better alternative to it: either play with locked HQs or with HQs set to 0. Problem fixed.
So me, like all the other players who do not use this feature would rather not sit through 4-5 patches riddled with bugs because you decided to fix this. I would much rather see you tackle important stuff such as the fact that the Germans have perfect fuel supply in 1945 than such silly things. At least with changes that would realistically reflect the supply situation in the later war, the bugs would be acceptable, because implementing such a change is a net gain, and adds realism to the game, while changes such as the one you mentioned are trivial and therefore not worth the effort, time or pain in the a** that they will produce.
Anyway, I hope you don't take this the wrong way. I really believe that there is no need to overhaul everything. Most of the stuff in WitE works just fine, all that is needed is small changes over a period of time so that you ensure that the game is fun and properly balanced.