you made no point at all in those two paragraphs, at least none that would fit the part that you were quoting.
it's not a "design issue" if you nerf one unit, because it is too OP in one matchup, and thereby mess up all other matchups... it's not a design issue, unless you call mirror matches a design issue.
also (and i have to admit, i was never really good at it), if i remember TvT in SC2 correctly, if both players made it to mid game, the player with more vikings won like 90% of the time.
The point was that mirrors weren't "inferior by default". You need a faction that's designed around having multiple options in every situation. This is, of course, really hard to do, but it's far from impossible.
Also, "the guy with the more vikings wins" was true if both players went tank/viking/thor, which was the easiest way to play the match-up. Marine/marauder/medivac, tank/marine/medivac and sky terran were also extremely viable builds, though, although more challenging to use and therefore not very often seen below high level play.
And forcing a player to master two armies won't elevate the level of player overall by giving him a deeper insight into not just one both both armies ? By allowing mirror matches you do create a much more narrow player. And also one who might be a bit more limited when it comes to providing feedback for balance since they will only consider one side of the argument.
It'll elevate the level of the players, no doubt. However, we won't see quite as refined play in each individual faction as we would if you could focus on a single faction, simply because not all the skills you learn as one faction translates over to the other. Having the MG micro to stop flanks as wehrmacht isn't a skill that's directly beneficial to me as a US player. However, it still takes a lot of time and effort to learn; time and effort I could have spent on learning to flank with US instead.
The ability to make better decisions based on your experience with the other faction is the most valuable skill you'll take from playing multiple factions. However, that kind of useful experience can often be gained from high-but-not-top level matches as well. Besides, if there ends up being more than two factions and you're only forced to play two of them, you're not being forced to gain experience from both sides in all matchups.
The balance point is interesting. In my experience, high level players mostly seem to agree on what's too strong or too weak, regardless of whether they play multiple factions or not. Still, you're right in that it could improve feedback somewhat.
..also, let's pretend that the balance forums on GR don't exist. <.<
So me pointing out that they were bloody boring doesn't count for anything ? And wouldn't it rather be the point to balance the game and design it around the asymmetrical gameplay. That is the more dynamic of the gameplay modes. And rather what fits in more with the first CoH.
It does, and it's a completely valid opinion. I just disagree that the mirrors were all boring.
And you do risk that things which do not work in mirror matches but work well in asymetrical matchups could result in things getting removed. Simply for the sake of the mirror match.
That could be said about any case where there's more than one match-up involved. Granted, it's completely true and still a valid point, but it's more an argument against having more than just one match-up than it is against mirrors.