3rd DB, no. 5th, 6th, or 7th, yes.
Sunseri has been a liability in coverage all year and frankly I've been disappointed with his tackling. On the positive however he is a playmaker and seems to find himself around the ball a lot. Apparently I've been more pleased with Fulton's development than the coaches as I would rather have seen Fulton on the boundry with Menzie moved inside to star with Vinny playing only in the Money package over what's been occurring of late.
As for Geno, if the light is finally on, put him at star, the sooner the better and find roles for Vinny where his assets are best used, ie aggressive blitzes etc.