I'll be clearer : You cannot ask for both a historical and a realistic game at the same time. First and foremost, what is "realistic" or " makes sense" for us is not always the outcome of history, no matter how you want to spin it. Thus, Rome, when it became the first world power in Europe, was utterly unrealistic by all standards : it did happen nonetheless. We can study the growth of Rome influence, we can infer why it became what it became, but it does not dissolve the utterly nonesense of its power by as soon as a few centuries later after the Punic Wars. History is full of those surprises.
Deal with it.
And I will even add : You cannot ask for a historical game because then you will have no game left at all depending on your definition of "historical". If you mean historical in the sense of having a historical setting, displayed by symbols, languages, numbers of unites in 1936 and whatnot, then the game is historical by all means even when Estonia gets to puppet whatever it wants. If you want it to be historical in the sense to follow the exact same path than history, then you are not really playing ; at best, it would be some kind of book. Of course, in that regard, Estonia does not get to do what it wants. No one does. The Allies win each time. But if you are meaning historical in the sense of what should or could have possibily happen in your own, singular opinion, then you are facing the same problem that we have with Rome - a.k.a. there were no signs it will happen and it did nonetheless.
History will surprise. If the game can surprise me, the better.