Given the following assumptions:
What level of mana troop do I need to charge a medium speed red hero in 3 more tiles after this?
Lvl 17 Mana troop will do it
I believe you only need a lvl 11
Each mana tier is +2%
Mana troop tiers are at 5, 11, 17, 23, 29
Average heroes need lvl 23 Mana troop for 9 tiles. +4% is like two tiers so that drops to needing lvl 11.
Edit: Misunderstood the question, Assuming 6 tiles without bonus already so yes, lvl 17. Lvl 11 would give you 9.93 Mana (just short of 10)
average heroes take 10 tiles total to charge.
6 tiles have been gained
leaving 4 more tiles to gain to reach full mana
assuming you start with a level 11 mana troop with a 9% bonus that means 6x1.09= 6.54
now add 4% more for a total of 13% on 3 more tiles 3x1.13=3.39
3.39+6.54=9.93 NOT enough
you need 16% mana generation total for this to work
So thats class bonus plus level 5 mana troop or
costume bonus plus 2% class boost and troop level 1 or
class 20 bonus troop 5
costume bonus and level 5 troop
and possibly a few other mixes
Lets try level 17 troop
6x1.11 =6.66 + 3x1.15=3.45
3.45+6.66= 10.11 That works
Just wanted to show there were multiple ways to get to this
Lvl 17 would work
6 tiles at +11% = 6.66 mana
+
3 tiles at + 15% = 3.45 mana
Total: 10.11 ✓ mana bar full
I know i forgot to put that in I was editing as you replied
Same. I had already edited mine when I realized I misread the question.