Thank you very much for help 
I got 2017 family consisting of Alberich, Perseus and Musashi.
If you think of Perseus and Musashi as fast heroes, they are behind with current heroes, but if they three together + mana troops make them very fast, they are stronger than very fast heroes
Fast heroes are charged in 8 tiles, which means that they are charging 12.5% / tile.
If you want a hero to be charged in 6 tiles, then they need to charge 16.66% / tile.
16.66 / 12.5 = 1.333333333 = you need 33.33% mana boost in order to have them charged in 6 tile.
Then they really did 2017 family nasty
So 15% mana gen from family (max) and 15% mana troop is 30% 
Where can we get extra 3%?
Thank you for quick math!
Probably need Xnolphod, Toxicandra or such to achieve VF realistically
Alberich is Druid.
It’s class can give him 4% extra mana generation.
Either another hotm with 4% element link. But I think all of them are slower, so that would only work later in the fight.
A hero who boost mana via special.
Or after firing albi once they all get mana each round, should be enough to charge the other 2 with 6 stones…
Yeah, but as fas I know, Albi also cant charge in 9 tiles… Having 34% mana gen.
Yeah, sorry he is slow…
Slow = 12 tiles = 8% / tile
For 9 tiles he needs 11.11% / tile
So he needs 11.11 / 8 =38.88% mana generation increase.