Man, your take on history has me openly laughing.

You know how the Mamluks came to be?  Christians Copts, Turks, captured European Christians, Persians, etc. were forced to convert to Islam or be killed, and then molded into outright fanatical soldiers.  They only inherited the caliphate because the Mongols invaded and wiped out the entire eastern side of the caliphate, including the capital in Baghdad.  The Mamluk commanders in the Abbasid's army had a military base in Egypt, the Mongols never got that far, and Cairo became the new capital by default. The Mamluks aren't a sign of Islamic tolerance, they are a sign of their power to force their slaves and defeated foes into service, who inherited power by historical accident.