You are changing your argument halfway through. Your point was that no development had been done on the code, not whether it was released to the public or not.
Hair-splitting. No development that public at large can see, buy and judge. Anything else is irrelevant because we can't see, nor we should be interested at all, in CSO work for military customers (I for one am not even interested, why should I be?).
You can hardly score it down because they gave the public what it wanted not what you think they should have wanted. Aside from which, I don't see professional reviewers knocking 25% of every new, good RTS, FPS or MMORPG release just because we've seen most of what they have to offer before.
Reviewers routinely knock 5-20% off blatant copies, copypaste sequels and totally un-inventive titles. Go one step further and try doing 1:1 re-release of 8 year old game and you'll see up to 30% knocked off of it, or being completely ignored, on the grounds that there is nothing new to review at all.
In that case, if you were consistent, games like Battlefront and the Decisive Battles of WW2 and Airborne Assault series could never score over 70% either. They approach 2007's best technoogy, knowledge and art no more than CC:CoI does (except, possibly, a little AI development).
Oh I think they do, at least some of them do. I have never been a huge fan of Decisive Battles series so I kinda agree there.
In general I agree with what you say. COTA scored less than HTTR did in my book, even though there were some significant developments to the main engine in between the two, and unless some significant imrpovements are forthcoming the next game will score even less (but still pretty high, because the main engine is not that old or in need of updating, and is still on the bleeding edge of today's wargaming "technology"). Take UI for example. COTA UI is almost perfect wargaming UI for today's standards, while CoI UI is simply atrocious for today's standards and completely ignores any UI developments we have been witnessing past 8 years or so (zooming anyone?).
I wouldn't change one single thing on COTA UI *NOW*, but perhaps in 2015. I will consider COTA UI ancient and very bad. I hope I will, and I hope COTA successors will be up to par by then.
Also, game series that apply the same engine on new battles and campaigns each time may, and will, be blamed for "cookie cutter" approach, but that's different sort of blame from what we discuss here. I think it's fair to say ALL wargame developers and all game developers in general use "cookie cutter" approach to a degree. Cookie cutter-ing new campaigns from the old engine is not the same as re-releasing 8 year old code, 8 year old UI, and saying "oh we did some real work, trust us, it's just not for you guys".