Ive build all guilds so far and the hardest one to get is Masons which ive only got in 3 campaigns, 1 in Milan, 1 in Thessaloniki, 1 in Zaragosa if im not mistaken. Ive never had your problems though Sinan and i guess its a pain, maybe you should try not to reject an offer if you get one even if its not at the city you want it maybe it will help heh.

Oh and the AI only seems to build Thieves guild, Explorers guild and Swordsmiths guild as far as i noticed.