From my previous post:
Woods
Heath
Iloka
Thompson (16 game starter 2017 Giants)
Donovan Wilson (Draft Pick)
After Woods returned from injury starting with game 3, Frazier only played 50 total snaps on defense. He only played 6 snaps after game 7 and 5 snaps in the playoffs. Heath injured his wrist late in the season and played with 1 hand afterwards but they didn't sub in Frazier on run downs like the previous DB coach did in 2017.
McClay and Chris Hall expressed more excitement about Wilson than the other late round picks. He reportedly showed good awareness in the rookie mini-camp.
Thompson is 6-2, 212 and started 16 games at FS in 2017 which means he has at least OK coverage ability and SS size. He didn'r play on defense in 2018 but I think that's because he was not with the team in training camp (signed before game 6).
It's possible they only keep 4.
Also the 5th Safety might be competing against a 5th or 6th CB. They carried 4 CBs most of last season and those 4 remain plus 5th round pick Mike Jackson and the 6-4 udfa as well as special teams "ace" Goodwin that was activated for the playoffs last season.