When I look at the detail and effort that went into the IGC, I am disinclined to simply say that a scenario editor assures us of IGC II. I believe that it is important to realize and acknowledge that the IGC was a collaborative effort by a number of people to both understand the game engine, and utilize that understanding to extend its historical accuracy. Indeed, reading the threads on IGC development provides one an impressive, refreshing, and encouraging demonstration of human cooperation at its best. These people were very successful because they spent the time to test ideas carefully and recurrently, and to look far afield in their research.
A scenario editor merely dumps into the hand of the novice what the IGC developers learned through hard work, minus the historical insight - and obvious respect for history - which the IGC crew brought to the project. I give great credit to Paradox for designing a open system for the game, but even greater credit to the IGC team for sacrificing their time to enhance the EU1 game. We, as game players, would be very fortunate if such a collaboration were to happen in EU2 - however, it will be an issue of people rather than software.