Tanks for all the advices you guys provide!
let me clarify myself better.
Well, first of all, this problem with AT didnt come out from any practical situation i was facing. I was trying to create a theoretically good composition of Infantry Corp with some flavor, in a context which:
1. i would concentrate most of my Armour in several army( Panzergroup) and rest parts of my front line, will be most likely consist of Infantry.
2. I micromanage all my divisions.
3. These corps need to be jack-of-all-trade ( and of course master of none) kinda type of things, consist different types of divisions to fulfill different kind of missions.
4. Very hard difficulty
5. The game version is TFH.
The last one is where the problem came from. Before TFH, i really never bothered to use any fancy support unit, my infantry divisions were exclusively consist of only 3 infantry brigades, with the set in mind that i would rarely use my infantry corps to attack well defended lines unless i have good number advantage, in which case the support unit doesnt matter that much anyway. The saved IC would better be used to produce more planes and tanks. I havent played HOI3 since TFH came out, and just again picked up the game recently, (i think you guys might already have had a good amount of discussions about the "new" AP-mechanism, although i didnt find the answer of my question through forum search). I dont want to overlook the AT now, and dont want to place myelf in a bad situation against the enemy armour because of that. ( Although im not certain of the real impact of the "new" AP-mechanism) And i really dont want to build too many ATs because of my old maybe outdated impression of it as a really bad support unit.
So then there's the idea that if the AT provide AP protection to all the divisions in a battle, i would build 1 AT division for every corps as a reserved countermeasure to enemy armour attack; if not, as many of you stated, i would probably go back to my old way and again dont mess with them at all...Which is kinda sad because the new Mechanism was the main reason why i want to re-explore the game and re-design my army composition, and now it looks like nothing had really changed :unsure:.
again thanks for all the replies, some of your advices will definitely be included in my future experiment.
You may consider this. It is really beneficial to have atleast one support brigade in each division.
Firstly, it will allow your division commander to gain the battlemaster trait.
Secondly, if you prioritise Battlemasters in every HQ above division level the trickle down effect means that adding a single support brigade to a division will yield a 15% increase in combat effectiveness rising to 25% if or when the division commander have/or gain the BM trait.