This is one of my favorite doctrines and while it's decent enough for the Osttruppen, many other abilities on it are simply unviable if you want to be competitive. I'd like to highlight the biggest issues and suggest some improvements for them.
Stug E
While this unit has good splash damage and long range, it often won't kill any models even with 2 direct hits. Enemy squads tend to shuffle around infront of it because of the lack of any immediate danger, which other units like the Ostwind, Scott and Brummbar would punish heavily. I'd therefore suggest to allow it to upgrade with a pintle MG for 30 munitions (same as Stug G) to allow it to finish off damaged models at medium distance.
Concrete Repair Bunker
This building simply has bad price/performance. The Soviet equivalent has 300 HP, costs 125 manpower and 45 munitions and provides 4 automatrons. The repair bunker has 960 HP, costs 380 manpower and provides only 3 automatrons. While I do feel the Soviet equivalent should be more cost effective because it occupies a whole commander slot and is obviously more vulnerable, you pay a x2,5 upfront cost with the repair bunker for each pio model over a fresh pio squad, which is just too high. I'd suggest the automatron count gets upped to 4 and the cost changed to 250 manpower and 60 munitions.
Concrete MG Bunker
Has bad price/performance compared to a normal MG bunker. It takes much longer to build, provides less sight, takes up 2 pop and costs an immense amount of resources, only so it can take 3 more shots from an AT gun (from 3 to 6). I'd likewise suggest the price to be changed to 250 manpower and 60 munitions.
Sector Artillery
While this ability received some love last rework, it's still one of the more lackluster Ostheer abilities. Compare it to UKF's Perimeter Overwatch for example:
- Slower tracking:
https://www.youtube.com/watch?v=tDf6SDp1uX0
- Duration of 45 seconds compared to 120 seconds.
- Only affects selected and adjacent sectors, not all owned sectors.
- Doesn't increase sight around capture points, while Overwatch increases it with 200%.
- Similar firepower (two offmap arty batteries vs 2 howi's + irregular offmap mortar and arty battery).
- 200 munitions vs 225 munitions.
In my opinion, the biggest problem is the slow tracking making it ineffective against enemy squads (and vehicles) that are mobile. I'm not saying it should hit them while moving, but the shells should atleast be somewhat on their tail. Also, the short duration means it's mediocre at area denial. The ability will probably be over after the initial engagement, so won't help much with denying your opponent from capping if you got forced off. I suggest to reduce the delay between enemy position and shells landing by around 1 second and to double the duration to 90 seconds.