[Cohen]

Zen Mod take care only of their frailty issue.

With almost no starting pathes or 1 as starting path, they can't be great mages ... they pay a lot of points to even get for a 0 lvl to a 4 lvl in a path! (10+16+24+32=82 pts).
They're so not suited for heavy spellcasting, nor for heavy blessing, nor for combat, and they don't provide combat skills to take out province in solo.
They're good to mixed forging and site searching (and it's damn slow, and if someone rushes you with any SC pretender type you're so dead...) so probably their usefullness reveals in a long term game ... but I'm not so sure if you take 1 province/turn (with your army) meanwhile the enemy start taking 2 provinces/turn (1 with army, 1 with pretender) thus having potentially twice of your gold and gem income, thus having more stuff/items/castles/temples and supplying his lack of magery with probably amazons, druids or good magic sites that he've found in his superior number of provinces.

Frailty here is the same in Zen mod, but they at least could excel in spellcasting or blessing (even a human pretender should be better to rely on good blessed troops/army than a powerful pretender that is strong on his own).

Don't forget the Scale change, that usually will lessen the points you can sink in your pretender magic.