Faldage: I see no difference between Silver Pigs and The Silver Pigs
Without knowing what the silver pigs are...
Try this. Conceptualise a silver pig. Now think of a few more and you have Silver Pigs. Now show me a particular herd of silver pigs, and you have The Silver Pigs. Maybe there is an assumption of definity (can I ® that) in the US which negates the need for "The".

What I don't understand is the reader's problem with "ears of corn". It actually makes more sense to me using the American definition than the British. An "ear of corn" is a common term, easily visualised, and made into headwear with not much difficulty. I have never heard the term ear of wheat nor can I imagine how an ear of wheat would look. Weaving the headwear out of wheat defeats the stupidity (and corniness) of the idea.