There are a few passive abilities in this game in which I wish they were merged into one, as making them separate would be a waste and stupid, like Imagine if you needed 2 separate doctrinal abilities to have riflemen build mines and sandbags, pretty stupid, right?
So there are a few groups of abilities that should be merged, as it would greatly improve a few commanders and hopefully make the abilities themselves useful too.
So lets begin
Ostheer: Defensive Fortifications and Trenches
I don't understand why you need two specific different commander slots to build trenches and tank traps. OKW can build trenches, tank traps, and flack emplacements all in one ability, and can build bunkers and mine fields in another. It should be combined into this one ability:
2CP: Defensive Fortifications
_(Infantry can now build trenches, Pioneers can also build tanks traps.) _
See? now wasn't that hard?
Now, Defensive now has an open ability slot, so we could put something actually useful in it! like the Unused Urban Assault's Forward Supply Station or another defensive orientated ability of your choosing!
Soviet: Tank Traps, PMD6 Anti Personnel Mines, and PMD6M Anti Light Tank Mines
Again, why do this? lets merged them
2CP: Field Defenses
(Allows Conscripts and Combat Engineers to build cheap and quick to place anti-personnel and vehicle disabling mines, Combat Engineers can also build tank traps.)
It gives Tank Hunters another AT tool in their belt, and allows another ability to be placed in Defensive Tactics. Like the Unused Not One Step Back Tactic's Hold the Line ability or another ability!
USF: Riflemen Flares and Rear Echleon Flamers
I don't know why flares, something that nearly every Soviet unit has as a vet ability, is used a commander ability slot for this doctrine. Also, I don't know why they are at 2CP too. As much as I want to give riflemen flamers back, that is a different story for people to QQ at. so for now, lets merge them
0CP: Pyrotechnic Training
Rifleman can now fire flares to reveal the area, Rear Echleons can now use Flamethrowers
Nice little merge, and the empty slot could be nearly anything riflemen relate! Like Riflemen Demo Charges, Riflemen Ambush Camo, or Combined Arms, ect. ect. ect.