Unfair Wizard upgrading

Has anyone noticed that when upgradig a Wizard from lvl 4 to 5, the attack and hit poit increase is crazy high, but when going from lvl 5 to 6(max) it's like a 1/4 the increase? This is crazy. Im paying more loot to upgrade from lvl 5 to 6, and only getting 1/4 plus attack and hitpoints than the last upgrade. No way! Dont agree with this at all. Please bring the attack and hitpoints, down for lvl 4 to 5, and bring them up for lvl 5 to 6.

please comment if you have any opinion on this. Thanks!

When you will get to upgrade them to level 6, you will find out how that small damage addition is actually very important. Also I don't believe they should lower the level 5 because the wizard is currently a unit which is part of a lot of attacking strategies for th8 and th9, but in the same time I don't think the level 6 needs to be increased, not to make it too powerful. In my opinion it's fine as it is.