I have a bungalow with no soffets some roofers are saying i need a ridge vent and one is saying i don't. what?

Put the ridge vents in and put a louvered vent at the gable ends front and back soffet vents are good only if you have baffles running up to the top of the roof.The gable vents will allow air to flow in and out the ridge vent to keep the roof cool and last longer.