Now I am not saying that the Germans could not have made better decisions, and I am not saying that the T-34 was not a good tank for the time, but had the Russians not had all the support from the other Allies they would have lost even with the poor decisions that the Germans made, and the poor decisions that the Russians were making would have made it even worse. If the Russians had tried to make tanks like the Panther, Tiger and Elephant than I think (partly at least based on my reading) it would have gone very bad for them. One reason from several of the different books I have read they talk about how lots of the Russian equipment including tanks were only built for at most one battle some were worn out before one battle was done, it was just they made so many, now if you were trying to fight "quality" with "quality" but were turning out junk that does not work well for you.
Oh, I completely agree here. The Russians played to their own strengths, such as they were, and refrained from trying to match the Germans in their strengths. As Stalin reportedly said: "Quantity has a quality all of its own."
Two things I see here, first you are right that the IS should have just walked over the Clans based only on numbers, I can not think of a "fair" fight between Clan and Inner Sphere where the Clan based on table top game rules stand a chance, they just do not have the armor. Yes the amount of blood that would be spilled on the IS side is going to be massive but they will carry the day. The second issue that I see is that the Clan does not pay a premium for clan tech as that is standard tech for them so you are rendering your argument mute. With that in mind you get one cluster of Clan OmniMechs for about 650,000 or so, and on the other side the IS gets about one regiment of 3025 mech. So no RCT, no support forces (unless you cut the number of mechs), will it be enough to win? I still say yes, but it will be a bloody battle and it will come down to the amount of armor on the IS side (more mechs more armor even if less per mech).
Now if we were talking real world ranges and real world tech advancement I would bet on the Clans in the above fight but that does not follow the rules as written or even intended. It is a game first and formost. }:)
My point was, even in war, money (or whatever other resource you choose) is still a bottleneck. You have only so much money to buy mech/tanks/infantry, or only so much steel, or so much rubber, or so much manpower, or whatever the critical resource is. So you´re going to optimize how you spend that resource.
The Inner Sphere´s constraining resource is the capacity to produce highly sophisticated military equipment (such as mech and fusion-powered vehicles), which is abstracted in C-Bills available to purchase units. So it makes sense to acquire boatloads of cheap and individually not particularly capable units (ICE-powered vehicles and infantry), backed up by more modest numbers of moderately capable units (3025-era Mech or even the cheaper (standard-engined) upgrades and 3050s/3060s era models). That will be hard on your manpower, but the Successor States have more manpower than they know what to do with.
The Clans´ constraining resource is the capacity for churning out trained combat personnel. Those personnel are individually extremely capable, but there are not very many of them, so it makes sense to spend lavishly in terms of C-Bills to give each of these rare and extremely capable personnel the most powerful unit available to maximize the effect they will have on the battlefield.
Even if we restrict things just to Mechs and assume the Clans pay no mark-up for their own equipment, that three-trinary cluster should work out to 700 million C-Bills or so, for which I can get a reinforced regiment of 3025 mechs, 140-ish units strong (I´m assuming, out of laziness, that the respective per-unit price average out to those of the Mad Dog for Clans and the Rifleman for the IS).
And you are right, the IS is going to win this one, even though it´s going to be bloody. The Clans succeeded (as far as they did) during their invasion because they did not spend the same amount of money as the IS. They spent, as I said above, MORE money to get the most out of what they had the least of - trained personnel. They could, for example, field 3 clusters to defeat an RCT; they´d spend 2 billion C-Bills, which they have plenty of, to the IS´ 1 billion or so. This allowed them to defeat an RCT of 6,000 or so combat personnel with 135 combat personnel of their own, meaning they spent a minimum amount of what they were the most short on - manpower.
To go back to the WW2 example - Russia went with the IS side of the equation, Germany with the Clan side. Germany´s problem was, among several others, that with the support of the US, Russia was no longer so inferior in military production capacity that Germany could have afforded building enough complex over-engineered tanks to deal with Russia´s output of cheap more-or-less-adequate tanks.