Here is my quick story...the previous owner (also original owner) rigged things together for 40 years. I am fixing/correcting/updating. We have a 1600 sq ft split level home. Our attics get incredibly hot. They have a new roof installed August of 2005. They had a ridge vent installed at this time. Here is where the problems start...I believe the prev owner installed the siding. The soffits have notches as if there are soffit vents. However, the attic still gets amazingly hot during the summer. There are also gable vents...Today I had my wife shine two strong flash lights into the vents from underneath. I was in the attic with no light. Didn't see anything. I tried to reach out but it's a sharp angle with nails from the roof just overhead. I noticed that the loose insulation is right against the angle. So, I went under the soffit with a hanger and poked through the slots. It was solid on about 3 vents I tested. This tells me that they installed the soffits but never had a soffit vent.

Any thoughts?

I am considering installing two roof mounted attic fans. If I fix the soffit problem would it alleviate this need???

Did you check to see if the ridge vent is working?

How do I check???

You need to climb into the attic and check to see if the insulation is tight to the roof sheathing in the soffit area. Also check to see if you see daylight along this area. If either its plugged with insulation or you do not see any light. Your soffit vents are not working.
You have a few options. Take the soffit down and re-install after cutting out the old wood soffit if there is one. Then re-install new soffit material with vent holes in it.
Or cut three inch holes and install new soffit round vents in them. This works but is fairly difficult to do working up high with a drill that wants to kick you off the ladder.
A siding company can replace the soffits and vents in about one day. I suggest going that route.
To check to see if the ridge vent is working you need to view it from the attic side. Is the plywood or roof sheathing cut back enough to provide at least 1-1/2" of space on each side of the ridge beam running the lenghh of the roof. More is better but at least that much. If you cannot see the soffit vent material from below in the attic its not working. Many roofing companies cut to little off the ridge when installing these type of vents makeing them worthless.
I would stay away from power mounted fans on roofs. Natural ventilation if properly done works best. AS once you install these fans your adding another hole in the roof, using power to run, raising the issue of mold if not properly controled by both a thermostat and dehumidistat. And there ugly to boot.

the vents will help to cool down but tiles like these roofing absorbs the heat.

If such tiles absorb heat, sooner or later they will transmit the same heat, both back to the outside air, and to the attic. Better would be a white roofing material that would reflect the heat back into the air immediately, but neither will solve the original writer's attic ventilation problem.