This is not a normal year, with Ford taking down their Dearborn factory for retooling of the F150. That's cutting out 1/2 of the company's truck manufacturing for 5 months of the year.
Not only is Ford having to re-engineer a completely new truck built of aluminum, but they're also designing the presses, machinery and robots to build vehicles never built on a mass scale. They were prepared to build and crunch as many as 19,000 truck bodies in order to get them right.
When Dearborn is up and running right, Ford will quit production of the last generation of F150's in Kansas City, tear out the factory tooling, bring in new tooling, rebuild the factory and teach them how to build aluminum vehicles. That's another 4 months of 1/2 production.
The numbers are skewed for this year--not valid. And how do you think the new aluminum bodied F150's are going to sell?
The new SuperDuty will be 100% aluminum and it's coming in 2017. It too will be a dominant vehicle. For the past years and years, Ford has sold more "light" diesel trucks than General Motors and Dodge/Ram combined. That's not apt to change.