Mike Iupati is a familiar name to NFC West aficionados. He was a Pro Bowl left guard for the 49ers before the Cardinals poached him from their divisional rival in 2015. He wasn’t quite the same dominant force in the desert, but he did make a Pro Bowl in 2015. When it was time to replace him, the Redbirds again went back to the NFC West well by snagging J.R. Sweezy from the Seahawks—who then replaced him with Iupati. Both players played well enough in 2019.
Intradivisional free agent signings like these will ideally strengthen your team while weakening a rival.