attic ventilation advice

When our roof got replaced in Feb., the roofer took out the powered attic fan and put in 6 O'Hagin vents instead, all up high. The attic is now an oven (over 120 four times last week, 137 today). O'Hagin dismisses the value of the 20 eave vents (3" x 22") we already have around the perimeter and says to put in 6 more of their vents, down low. See attached drawing. I would rather cut 1 hole in our new roof for a powered fan than 6 holes for more vents. But I want a ventilation engineer's advice about how best to solve the problem.