if the rail is at 12.2 volts then they are getting the correct voltage and wattage should not be an issue b/c fans only pull between 2-7watts. Big fans push alot of air just over a large area so it could be they are running at the right RPM and pushing the correct amount of CFM but just over a large area. it will not feel like it is moving as much as say an 80mil moving the same amount of air... (AKA theoretical focus flow.) (that would probably be one Crazy loud 80mil. lol!) Keep in mind the larger the fan, generally the slower the RPM for the same airflow which also reduces noise. that is the major benifit of larger fans is reduced noise the area the flow focuses on.
here is a 80 mil 40cfm that runs at 2800http://www.newegg.com/Product/Product.aspx?Item=N82E16835185127
compared to a 140 mil 43cfm that runs at 800 RPMhttp://www.newegg.com/Product/Product.aspx?Item=N82E16835185156
the 140 mil fan will not look or feel like it is not moving as much air as the 80 mil but it is just over a larger area.
anyway if you feel they are not performing as intended i would contact the manufacturer and see what they say about it.