Do we know how combat and movement "work" yet?
If it is a case of "everything shoots at everything" as in previous HOI games then there is less scope for individual battalions to have an impact on things. Broadly, what matters is the total attack number on each side, and you can add up lots of things in different ways to get to the same number.
A different combat model would give more differentiation. For instance, the role of a Tank Destroyer battalion in a division isn't just that it increases the number of AP weapons in the division. It also makes it more likely that those AP weapons will be in the right place in a fast-moving situation, and thus that the division will achieve a local concentration of force against the tanks threatening it. Equally, a division with 5 Tank Destroyer battalions isn't 5x as effective against an armoured division as a division with 1 TD battalion, because once two TD battalions are engaged against the enemy tanks there isn't space for any more, and you end up trying to do reconaissance and protect supply lines with the TDs, which they are rubbish at.
In a similar vein: not having an engineer battalion means bridging rivers and attacking obstacles is more difficult. Having a full brigade of combat engineers shouldn't much of a bonus to brridging or to attacking obstacles - unless you are attacking a city or fortification line where there is an obstacle to be demolished every twenty yards.
And Artillery for instance - removing infantry and adding artillery might add to the overall firepower of your division - but do it too much and you risk having too few rifle units to actually take ground. Each Artillery unit can act synergistically with an infantry unit, yes, but just adding them both up to get a "Soft Attack" number will give an odd result.