The flaw in this argument though, is that iron is actually worth less than other resources (besides horse) to the Russian player.
I fundamentally disagree with you here.
Iron creates Swordsmen as well as other buildings, presumably the Russian Krepost will require Iron. More Iron will always equal more swordsmen. More horses will always equal more horsemen. Seeing as these are the strongest units during the Classical Era, more of these will always be better.
The only way your argument makes sense is in a trade vacuum where resources are not actually used for anything.
But if it's like I imagined it to be initially, then it is not as you say that they will lost the power to trade it at all because they will always be trading 2 for 1. They will just as readily trade 2 for 1 where horses and iron are concerned because they are also receiving 2 for 1. Their willingness and ability to trade should be no different to anyone else out there. If they truly believe they are losing out in the deal every time they trade off one of their irons for a banana then they are not looking at it logically.
The crux of your argument, as I see it, is thus; "Russia should be willing to trade away two Iron for any other one resource as they will have an abundance of Iron." There are a few problems with this line of thinking.
1) There is no guarantee that Russia will have an abundance of Iron. We've all played those games where the resources just don't land right. It is entirely possible that Iron will be a scarce commodity and every single scrap of it will matter intrinsically. Simply stating "Oh they have alot of it so that makes it ok" is not adequate.
2) You fail to create a distinction between Special Abilities and Resources. This is incredibly important because you attempt to paint the picture that Russia gets the leg up in the game as a whole because they have an abundance of Iron to trade for other resources.
However, you fail to recognize that the Greeks still have their Special Ability in tact. Let me try and be as clear as possible.
Let's say that the Russians have 2 iron nodes, giving them a total of 4 iron because of their special ability. Let's also say that the Greeks have 2 iron nodes, giving them a total of 2 iron.
This means that the Russians are receiving 2 iron as a benefit from their Special Ability. In this vacuum, it appears as though the Russian ability is unbalanced and scary. However, you fail to add in that
the Greeks have a special ability that allows them to lose City State influence much slower. Yes, the Russians do have a trade advantage with Iron and Horses. That is absolutely true. They also do not have a bonus to city state trade. You
must factor that in if you are going to be talking about trade as it is effected by Special Abilities.
The Russians will trade away 1 iron to receive an equal value, not some ridiculous 2 for 1 situation. This is because it is their
Special Ability. It will give them a small trade advantage because it is their
Special Ability. It is supposed to seem better then normal trading because it is their
Special Ability.
It's all they have, and if you insist on comparing their Special Ability to someone who does not have a Special Ability that affects trade this way, of
course it will look unbalanced. If I were to say, for example, "The Greek Special Ability is unbalanced because the Russians have to spend twice as much to keep the same amount of influence with city states." I would be simply wrong, and people on these boards would most likely call me a fool, as they should. This is because anyone can see that if you compare a Special Ability to a Non-Special Ability, it's
supposed to look more powerful. That's the reason it's
Special.
The only appropriate place to begin the conversation is by saying that if the Russians have two Iron, and the Greeks have two Iron, the Russians will have a total of four Iron because of their Special Ability, and the Greeks will have a total of two Iron, as well as a 50% influence boost to City States.
It is only from here that one can truly begin to talk about whether or not something is appropriately balanced, or fair, because it is only from here that you can begin to ask the simple questions. Is 2 more iron equal to the Greek Boost to City States? At what point does it become unbalanced? 4 more iron? 8 more Iron? A 50% boost to City State influence is an extremely potent boost, and it would require an INTENSE amount of resources to begin to rival it.
This is what I mean when I say that people need to stop and think about the Russian Special Ability and realize that it isn't unbalanced. People have this gut reaction to "More Iron Equals More Swords!" and they picture this situation in which a massive army of swordsmen simply marches unimpeded across the field. What no one who is arguing against the Russians ever factors in is that every other civ will
also have special abilities.
You cannot, you
must not have the conversation without factoring that in, or else your entire thesis is flawed.