There are 3 parts before it, and 1 after (I'm not including the sixth one because I haven't played it), it's not hard to guess what it should be, right?

Demanding that the fourth game be a continuation of the third would be fair if it had been stipulated in the development contract, and even more so if the client had paid for it.
Based on these considerations, instead of inventing locomotives and cars, they should have simply harnessed more horses to the cart... Evolution (of the game) took a different path, which is not worse at all - it's just unfamiliar. The developers were able to create a quite balanced and original game.
Another question is to choose the game that you like more, and then improve your skills. After the third game, I could no longer switch to the second, and even less to the first Heroes. But switching between the third and fourth games and back is no problem. The question is not about what someone likes, but about the fact that some, if they didn't get what they wanted (or couldn't figure it out), immediately consider it to be rubbish, garbage, etc., not worthy of attention. It strongly resembles the fable about the fox and the grapes.
Any monotony, no matter how good it is, gets boring. But at the same time, there are a huge number of fans of empty TV series who eagerly await the release of a new 1000-episode movie about nothing. And they are unhappy when this empty series suddenly ends.