Your enemies at this scenario are the infamous Berbers and Moors, so to speak, they use camels and knights as the backbone of their army. Don't waste time trying to train a balanced army, you just need Spearman-line units for your defense and soon, for destroying the muslim forces.
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1) Gather all sheep outside your walled base and bring to your villagers.
2) At 15 minutes mark, both enemies will try to break through your walls and try to destroy one of your Town Centers (and if they raze one, you lose).
3) Don't underestimate their camelry and cavalry, if you are behind technologically or bad in resources, you must have more than 20 spearman/pikeman ready to fend off their first wave.
4) Your ally is most useless for this scenario but you can trade him soon and get 78 gold per Caravan travel. He will be on the east side of the map and his map vision will be revealed in 15 min mark.
5) When you go for attack finally, use Halberdiers, Throwing Axeman and Trebuchets. They are enough to level their cities.