I've made just four for the moment. They are intended to be weighted against the human player. This is quite tricky as when you give an AI player an extra advantage they quite often use that to fight other AI players so helping the human player.
Freelords scenarios are based on the save file and the format of this gets updated quite often. The map file you use must be of the correct save-file version for the version of freelords you have on your computer. I tend to be quite sporadic at maintaining the scenarios so you may well find a more recent version was included in the Freelords package that you installed. You will probably find it in the same directory as the tutorial scenario (probably /usr/local/share/freelords/map). It may be simpler if you copy them into your .freelords directory.
Bear in mind that the AI improves with each release so that a scenario that was written to be a challenge may become quite impossible to win.
These are for save-file version 0.3.6d, which is for the current, 0.3.7 release.
This is for version 0.3.6c, it differs from the version found in the map directory.
These are for version 0.3.6b, ported by Andrea Paternesi
These are my originals for version 0.3.5d.
I was never able to get them to work as a map file for that version so I used to load them like a normal save file.