Keep in mind that WFA changes come along with EFA changes:
https://www.coh2.org/topic/61465/eastern-front-armies-revamp
So, let me help you here, by bringing up what you are looking for:
The reason why walking stuka (or any unit) should not be allowed to demolish buildings from afar in one go are the garrison changes. So, let me also look that up for you here:
Given the delay in hoping-in/out of garrisons, and the cost discount on the walking stuka, it would be completely unfair for the unit to wipe units from afar.
Finally, note that the walking stuka receives its incendiary barrage at Vet0, which you can use to burn down garrisons.
Which are the other critical flaws that you're referring to?
The problem is mr smith is that there are no changes in the patch for field hq only for the mod and having to scoop out 40 munitions with no guarantee of even destroying the building especially the larger ones is a massive drain on resources just to attempt to counter a broken mechanic.This is like taking the roof of a house in april and saying the rain is not in scope.
Sure I will share another, In the patch notes it says the mortar pit has been reduced to a target size of 1 despite its massive size and making it more vulnerable to small arms.
The flaw is 90% of the time a bofors is protecting a mortar pit and will decimate any infantry or light vehicle in seconds regardless if they try to retreat or not. Thus making the most liable counter for emplacements AT guns useless. This makes countering emplacements even harder as you need 2 separate strategy's to kill emplacements.
The Bofors is amazing against infantry, light vehicles , does a decent job at medium tanks , and even knocks hp off heavy tanks to add more wood to the fire it is also a bracing artillery piece. Utterly astonishing for 280 manpower and 30 fuel.
I think it would be far better to have things as they are in regards to emplacements (apart from mortar range and reducing the bofors insane squad wiping potential) but have brace drain manpower when used so it can't be spammed . This will be a far simpler and more effective way of balancing emplacements especially considering the ultra cheap cost it has.