I don't disagree that what you state may be a better way to look at it, but by the same token, license fee to annual revenues is an admittedly handicapped metric to use, as it can only correlate properly to the extent annual revenues are generated by the licensees infringing products.
That being said, Fujitsu paid at a ratio of $1/$1356 based on the data I have of $31.6M paid on $42.85B in revenues. However, HP only paid $26.4M based on annual revenues of $94.1B, or a ratio of $1/$3564. So if Sony INDEED paid $16.82M or there abouts, they'd fall about mid way between HP & Fujitsu. Again, it doesn't seem extraordinarily cheap to me, and the cache that Sony added to the MMP License List may have been important enough to warrant it.