I have just checked .

Food consumption reduction starts at VIP 11. but is only -4%

Hero reduction depends on how many skill points you have, and how you have distributed them.

 Reduction is listed about halfway down the middle column of skills.

I don't know is the answer, but there is a way to check , which I was going to suggest the last time I replied.

See what the numbers are if you let VIP run out ,or  if  you rearrange/cancel the hero skill points. 

Compare them.

My other thought is, its probably connected with other questions about the game along similar lines.

I suspect many people just do the upgrades,etc, because they believe it helps ,because they believe the 'X' % promised is significant, and they believe they are getting what it says and most never check . 

Few question the mathematics of it .

Some do.

Some of it is to do expectations, and with the contradiction between the understanding of the text, and the conflict with the mathematics.

Then some of the clever people explain how it works, but it mostly goes over my head.

Its also connected with what part of the thing in question is the % reduction taken from, and how big the starting numbers are.

 Example .

The 10% hero energy reduction day.

Later in the game after doing research, it may take around a 100 units of energy for one hit on a level 1 invader, at the start of the game with little research done,it might take 400 (I cant remember) but what ever it is,here the actual energy saved is a more significant number.

10% is  still 10%. 

Development, it seems reduces the importance of the boosts, and additional boosts of their impact. 


However, this doesn't seem to matter much to the kind of player who has currently maxed out the palace, presumably much else as well,already with L 10 hunt and who  is relocating around the kingdom and killing L 1 invaders one  after the other and at break neck speed with one hit.

So many ways to play the same game. I like to explore strategy and plan ahead rather than just knock off troops and invaders. I was just exploring the logic of allocating skill points that could be used in other ways. Looking for the best bang for the buck. 

Doing research I found it was difficult to find statistics for levels already past to verify whether my decisions were the best. I have completely reset skill sets for hero and shaman and of course crafted different sets of equipment. Then I get mad at myself for not activating the right set before I do something, LOL. All a learning process.