This area of the building can save you a lot of money down the road if done correctly
With this type of roof you need a lot of air moving in all the truss/rafter spaces from the eve (soffit) to the ridge (peak) of the roof to do this a continuous vent installed in the soffit works great allowing air into all the truss/rafter spaces.
The next thing is to keep a minimum of 1″and more is better of air space form the roof sheathing to the insulation install a spacer to maintain this area.
At my place a have minimum of 14″of air space making my roof attic stays within 5° of the exterior temp. Keeping the shingles cool, that will lengthen the life of the shingle as well as the roof sheathing.
I personally like wall vents for attic areas, and they give charm to the house at the same time.
If you can give it 1 square foot of air for every 250 square foot of roof, this will work great most guys install roof vents as to code 1 vent every 250 SF of house.
Remember you may have big overhangs that have to be cooled and the vents they are using only let out 61 qubic inches of air they are short by almost 2.5 times more vents are needed.
The asphalt type shingle absorbs heat and is designed that when the heat hits it, it re-melts the shingles into a uniform sheet of rock and tar.
On a wood shingles the wood acts like insulation and repeals the heat. A wood shake is a little different oh it repeals heat but it also has air gaps around each shake making the even cooler.
In doing so you can put in a smaller AC conditioner saving you on electric costs in the future.