NargottThis is not correct calculations for 3.33% bonuses at MMH5.5 mechanics. It's closer to original 5% bonuses.
The general point is that all bonuses are calculated for BASIC damage, not current.
For example (in 3.33% mechanics), +3 attack give +10% of current damage, but only if the difference is 0 (for example, 12-15 attack vs 12 defence)....
I am not sure I can follow the numbers below this line but I think I get what you mean.
Both attack/defense bonus and offense/defense secondary skill are applied on creatures base values and do not multiply each other. So creatures are always better because when a player gets them he also gets any attached bonuses for them while bonus is just for the base.
NargottIn short, real bonuses are less than basic. Having 150% number of creatures is much stronger than having "49.95% damage and 49.95% defense boost", even without destructive spells.
I think you meant 50% more creatures.