Sry for bumping the topic, but I had to give my 2 cents as well
I think most people dont realize that CoH has a very different combat mechanic compared to SC2.
In SC every unit always hits and always does the same amount of damage, it only depends on what upgrade each units has and whether or not the enemy has armor. However it does not matter what unit you fight against. A marine will still always hit and will always do his standard damage.
In CoH each unit has several modifiers against all kinds of different units.
For example:
A Pak does a certain damge x. This damage x is modified by the target it is shooting at. There are different modifiers for heavy tanks, light vehicles and infantry.
It also uses different accuracy modifiers. Many of you probably still know how the accuracy modifier of AT guns has changed several times during vCoH. Or Schrecks (vs. light vehicles).
On top of that, some units have specific modifiers vs specific other units, sometimes influenced by their veterancy.
So maybe you are already getting my point. The game is only balanced towards a non mirrored match up.
To give an example:
The US and british AT-Guns have a much higher penetration and damage output compared to its german counter part. Why? Obviously because of the asymmetric balance. Germans have better tanks, but allies have better AT guns.
What happens when a PAK is fighting a King Tiger? Well, pretty much nothing.
As a result, it would only be viable to fight tanks with tanks.
At the very least some units will become completely useless. That might be ok if CoH was famous for its large number of different units, but its not.
A CoH developer once stated that you couldnt just let Wehrmacht fight Wehrmacht. In order for that to be balanced, they had to change hundreds of said modifiers.
Also, much of the fun comes out of the fact that there are vastly different units on the field at any given time. Its a difference between having some volks/mg combo with a HT and some mines fight vs M8's and rifles or if you just fight rifles vs rifles and M8 vs M8.
Now they might have designed CoH 2 arround the idea of mirror matching, so that the mentioned problems wont be such a big deal. However the fact that mirror matches are usually more boring still stays. That is not only bad for the matches themselves but also for e sport. Maybe 2on2 would be more fun as there are more variations.
Still, I think its a hard task to do it right (dont forget the bulletins and commander abilities). If they implement it, it should stay in basic non ranked matches. It might be fun every now and then.
I'd much rather see a good variety in map designs, which will have great effect on how each battle plays out. That is much more interesting to watch and play, compared to mirror matches.
I also fail to see how mirrors can make a game more competitive. Its like saying shrinking the seize of a football goal makes the game more competitive. Its makes it different at best and more boring to watch (ok, yes bad example, but still
)