I'd usually say 4 too, but Michael and his companions seem too inexperienced to pull off such a complicated manoeuvre. Getting the ships organised, loading the troops, and actually getting to the target is a process in which much can go wrong; even more experienced commanders found it a trouble without extensive preperation. Following 1 means that Michael's inexperience is balanced by the Sultan's skills.
Remember, Michael isn't really cut out for the military side of things, and his company at present lacks men with extensive experience of waging war.