Scripts

By the way, do combat scripts work the same way in cities?

Cities have their own city scripts, whose functionality is limited to two intercepting functions for hiring heroes and creatures, and most likely common ones like mod, print, consoleCmd. Since all this can be done through a strategic map script, there is not much point in the existence of city scripts.
Or was the question about sieges?

Added 7 minutes later

There's just a pause and a unit of elementals appears. Without animation, sometimes, very rarely, it does play.

Perhaps this is a feature of creating this spell through a script.