i think youre right about the eagles/niners. both of them likely run over the lions like the panthers did.
i think the lions will try to make a move for a corner this year in free agency (and the draft). that's the one area where they are really talent deficient. okudah got benched at the end of the year and, quite honestly, played his best football as a safety in the box (against dallas) rather than as a corner. yeah yeah vikings game against jefferson, but that was mostly double coverage. okudah was beaten a lot this year, iirc. and was subsequently benched.
if i had to guess, i bet they dont pick up his 5th year option. they'll need a few corners in the next few years and they cant all come through the draft.