Look at the list of RHD UFAs and tell me which of them make sense for the Devils, and that the Devils would make sense for them, and that can be signed for $1M or less, with the understanding that that player will be in the press box/AHL if the Devils ever get healthy. It's an extremely short list of players. You're looking at extremely old players who've been a spare part forever, guys who've never had an extended run in the league, or players like Brodie. It's guys like Connor Carrick and Dysin Mayo they'd be looking at. I like the versatility of adding a 7th D who is an LHD who can play the right side a bit because the Devils have a ton of RHD when they're healthy.
Jon Merrill is another option, maybe, but he will probably be too expensive.
The Devils are extremely unlikely to find a 'good' player to fill this spot from outside the organization.