The infidels are occupying the lands of your ancestors, and it seems that noone can do anything about it.
You, Yusuf Al Harun, have lived for some time in Damascus, but has just received the worst news: Your father has been killed by the infidels, and they have taken over the oasis that is your heritage. You cannot let this happen!
You gather money, craftsmen, and troops, and leave for your oasis. You have what it takes to go to war, but you are not quite sure if your engineer from Damascus is skilled in constructions suitable for war, but he sure does construct nice palaces!
You arrive at the oasis, where four infidels warlords have occupied the most fertile and productive land, and left you to establish yourself in a less favorable position. It also seems that some of your fathers former subjects have changed their allegiance.
Can you oust the infidels from your heritage? It is entirely up to you!
Important Notes
This skirmish map is close to useless without the special AIVs that come with the "package".
The folder "aiv" contains 4 AIVs:
1 Abbot
1 Sheriff
1 Pig
1 Snake
which are not amongst the hardest opponents.
Rename your "aiv"-folder in the Stronghold Crusader folder on your HDD. Then insert the "aiv"-folder from the "Four Infidels" zip-file. Start Stronghold Crusader and place yourself - and your four opponents - according to the in-game instructions.
Before starting the scenario, please see, that your in-game identity is that of an Arab lord. This is important because of the above storyline, and the troops you receive when starting of the game
To maximize the fun (otherwise, the scenario will probably be too easy), you should use the settings most favorable to the AIs, whether you want to play a "Normal"-, "Crusader"-, or "Deathmatch"-game.
Have a nice game! :-)
Update
Updated the Sheriff AIV. Changed 1 granary to 1 hovel, which should ensure that the Sheriff can always produce troops.
You're right about the tower defenses. Initially, I had a vision of multiple AI troops on each tower, but it got complicated. Suspect there is a solution, and have thought of one - but haven't tested it yet (keep forgetting).
The ".sav to .map trick" might very well be the solution for another custom AIV scenario, but this time I really, really wanted to present it as a skirmish. :-)
Regarding custom AIVs, last night I playtested 2 snakes (1 custom AIV) against 2 original FF wolf AIVs (no player intervention). The wolves didn't exploit their small chances, and ended up paying the ultimate price! :-) It's good fun to play around with AI Village, but rather time consuming.