Have fun with fabrics. "Make everything your own !"
Not that you're listening,
But I would do a bench seat ( one long seat cushion ).
And make a couple of contrasting pillows.
Multiple seat cushions look 'cheapo' to me .
Multiple cushions came about
from furniture manufacturers trying to save money on fabric.
They can use much smaller cut pieces of fabric ( scraps ) to cover multiple cushions, they need a much larger piece of fabric if it is a large cushion.
( enlarge any picture for more info and a closer look )
Renee Finberg 'TELLS ALL' in her blog of her Adventures in Design