Where I find it interesting, the kids will get bored, and vice versa. I wouldn't want any simplifications; that's my opinion and the essence of my comment. I wouldn't want to popularize it...
It seems that, in your opinion, children of preschool age play Heroes, and that most players are of that age. I haven't noticed any simplifications in the 5th installment compared to the 3rd; only improvements. If you reason like that, then a car with power windows instead of a crank handle risks becoming a baby stroller in the future!
How can you explain to someone who started with the 5th installment what the spirit/atmosphere of HoMM is?!
Okay, I'm going to play HoMM1 and HoMM2. Maybe I'll discover that spirit you're talking about.