Well, you pointed out the one thing I've been thinking the last few days... The missile formula is actually meant to emphasize on the way missile damage increases (as in ppoint out that range affects it, that attack and defense are subtracted etc) rather than accurately calculate how much that damage is. Therefore the title I've used there is misleading and I should change it (or try to come up with a better, which however requires some serious testing and some serious time which I currently don't have)

If you happen to do any tests and come up with interesting results, please share. Missile tests are a nightmare, because results can differ so greatly from one volley to another that you need hours upon hours to get something tangible.