On the subject of Zmeys...
In my (first, SP CBM 1.92) game summoning these, I've had mixed success: I've been using them as lone raiders to fly into AI territories, great when lightly defended (e.g. up to 30 defenders), but they lose if they land in an army.
Doubtless I could do with more scouting for adjacent provinces, but I get too impatient if I see a juicy temple one ...
Am I not using my Zmeys optimally/sensibly?