Aquitania and Mauretania's deck pipes?


I've noticed in most of the footage of both Mauretania and Aquitania, their decks seem to be cluttered with a myriad of horn shaped pipes, as opposed to other liners (the Olympic-class for example only had a few of these pipes on deck) is there a particular reason Mauretania and Aquitania had so much of these pipes filling their deck?
The Olympic Class had large rectangular vent trunks at the front and back side of the funnel base (for ventilating the boiler rooms) which avoid the large vents as seen on the Mauretania. Also the 4th funnel which was used for letting off smoke of the kitchen, galleys and the fireplace of the smoke room was also used as a vent for the turbine engine room reducing the first planned large vents at that spot.