I thought it would be good to provide some perspective and discussion on evaluating relative cost/benefit of units. I would like to go into more depth on this as time permits. Some of this was already in a thread that is now deleted, but some of it is new. Various ways have been suggested to do evaluate the relative strength of units compared to their price. Typical ways include calculations based on attack, defense, and range. This would then be used to try to get most units near the same relative strength per cost. Another way often used in conjunction is to evaluate simulated battle results at equivalent IPC for both sides. These have some merit, but even together they still don’t provide an ideal solution.
First, there are some other things to consider such as, the old “rock/paper/scissors” aspect. Second, there is the historical aspect of some units actually performing favorably against other individual units (e.g. submarines, vs. more powerful surface vessels, aircraft vs. ships in general.) Third, the real combat value is rarely demonstrated in equivalent IPC matchups…instead it is more a matter of what sort of matchups are likely to result during play. Fourth, the impact on the overall game must also be considered.
The first two points above are closely related. Games (and weapons systems) tend to have some rock/paper/scissors relationships. That is why balanced and combined arms are favored. But also in a historical sense, it is not necessarily wise to assume a given value of two different units should have the same effective chance of winning. We hear a lot about spamming with subs or destroyers in the game for example…but when you look at what the nations built, you find an incredible number of these units to acheive a given aim. Some weapons went out of favor as a result of the war (battleships), some came into their own (carriers.) This is a reflection of their combat or mission effectiveness. Some were used in massive numbers by various belligerents: subs for Germany, destroyers/escorts/frigates/corvettes for the allies. One might expect the cost structure to encourage somewhat similar builds if the war time strategies were reasonable. This is complicated by needing to put each unit into terms of actual wartime cost by comparison so that 1 inf figure is not 1 soldier anymore than 1 fgt figure is a single fighter.
Third, real combat power is difficult to quantify and is most likely not represented by simple head-to-head equivalent IPC bases. Afterall, the attacker seeks advantage and net survivability of high value units…NOT equivalence. The potential error in just considering head-to-head, equivalent IPC matchups became apparent when I was looking at cruiser cost. As others have noted it is hard to beat an inexpensive “meat shield” or “fodder” type unit to protect the heavy hitting pieces. Therefore, with OOB unit cost there is little reason for a cruiser purchase because they have the same hitting power per IPC as a DD, but the cruiser still can only take one hit so it has 2/3’s the hit point equivalence. On a head-to-head equivalent basis 10 IPC cruisers might seem the answer…but this could be an artifact of putting high end units up against meat shield, with no shield of their own. A less aggressive 11 cost for the cruiser might be a better match for consideration of mixed forces. I’ve done some calcs based on 1CA+ 1DD, vs. 2DD; and incrementing up each side with DD’s each time at ranges of CA cost from 10-12. What I find is that the return on investment for the extra cost of a single cruiser in these DD fleets is favorable even at 12 IPC and of course increasingly so as the cost declines.
Gameplay/balance is another criticial thing to consider. We start with an initial placement. When contemplating buys and attacks, if the cost of one component (air, naval, or land) is adjusted up or down then it will impact buying in the other areas as well. This would shift game balance in many cases. So the fewer/smaller the adjustments, the less disruptive they will tend to be.