@newpaintbrush:
No, there is also the IPC gained from the surviving USSR infantry killing attacking German invaders. In addition, USSR also gains a positional advantage by trading infantry produced two turns ago for infantry produced four turns ago. Also, if Germany takes too long to take Russia, the Allies will win. The alternative is NOT attacking German held territory, in which case the Germans simply gain 2-3 IPC per turn. Do you understand what I mean?
Well, we are talking about trading for a singel small territory. It wont delay an major attack from Germany. When Germany goes for Moscow it wont be just a INF or two. However in small battles before Germany is ready for the big go, these kind of trade battles might happen. You are right about that a 2 INF and 1 FTR combo is a better trade than a 2 INF and 1 ARM, since the trading will be worth 6 IPCs instead of 11 IPCs. But is still trading as long as both side have a FTR to use instead of a tank. So if we consider that both Germany and Russia will have FTRs, then such a battle will just be a better trade than using ARM. I would say if Russia does not have a FTR to back up such a battle (trading), it is simply not worth it if Germany have FTRs! This is just easy math.
Germany will simply gain those 2-3 IPCs no matter if Russia attack and captures that territory since they will counterattack with INF and FTR and hence use the same tactic. As long as both sides use FTRs in such a trade battle, the trade will be 6 IPCs (2 INF) for 6 IPCs. If one accept the trade Russia will gain 2-3 IPCs per round and so will Germany. But if Russia does not have FTR the trade will be 11 Russian IPCs for 6 German IPCs to gain 2-3 IPCs, that is a net loss of 2-3 IPCs!!! That is the reason why Russia should not take on such a trade battle and hence those expensive FTRs Russa starts with are very expensive. Right!
In your scenario a FTR is a better unit than an ARM, but it is not always the case! Sometimes one want to stay in a just captured territory to beef up defense for a counter attack also it can capture a territory! Not to forgett the fact that AA Guns can targey those FTRs, wich makes them a risky buy! So I would say that the FTR and ARM complement each other as units in that way. They are simply good for different purposes. Hence the pros and cons are even so far. The true question is what justifies those 10 IPCs for 3/4 unit compared to a 3/3 unit for 5 IPCs. If we consider a fictive FTR unit that can move and attack land only, what would such a unit be worth? I say 6-7 IPCs, since such a unit mainly would be better for defense. INF still is the best defensive buy, so that argument is not very strong. I say the main reason for those extra IPCs is the extra mobility, 4 in movement compared to 2 for an ARM. That mobility advantage is worth at least 1 IPC. So those extra 3-4 IPCs, of buying a FTR compared to an ARM, is basically assignable to a better range (movement) and option to fly across see and to engage naval battles. I say a that the versatility of a FTR makes it worth at least 8 IPCs, but to be balanced for naval combats the price need to go up a bit. I belive that a 8 IPC FTR would become a game braker for naval battles (for mathimatical reasons not disclosed here). As the design for navy cost and capabilities are now, I say 10IPCs is a balanced price for FTR. Still 10 IPCs is hard to motivate for land based combats, and that is why I suggests the use of an air supremacy rule! Such a rule should also affect naval battles, to capture the historical importance of controling the skies and make CAs even more important! Your arguments for a 12 IPC FTR are indeed something I would like to here more about. As long as one can lower the cost without braking the game balance, that unit is not perfectly balanced for the game. That is the true reason for the reduced cost of a FTR in A&A:R!