DISCUSSIONS on “Rules for online games in HoMM3 and formulas for calculating player rating.”

In my opinion, you could give the Chupe a 50% debuff to combat skills and prevent it from casting spells on Expert difficulty, while giving the Black Sphere a +50% buff to combat skills and leaving the skill resistance debuff as is. When both spheres are equipped, they negate each other, effectively canceling out their effects.
The cloak should be reworked, as Vic suggested, into an equivalent of the blue hat for level 4.