The Giants are smart this year. You don't get a trophy for having the most amount of unused cap space.
They had a problem on the OL with injuries and a rookie starting at LT, not nearly enough talent on the DL with Selvie starting, mediocre LB's, and losing multiple safeties for the year in training camp.
Still they were 7th in passing yards per game and 8th in points allowed.
So what do they do? Go get the best pass rusher in FA who also plays elite run defense, a 350pound lane clogging monster, and they're upgrading the strong side from Selvie to JPP. They also sign a talented corner that forces turnovers.
Their objective was clear, improve the ratio in passing efficiency, a leading correlation in winning % while also forcing more TO's, another leasing indicator in winning %.
By upgrading the DL to force sacks/turnovers and stop the run, while adding another corner that can play man to man or zone, and create turnovers as well, it's hard to imagine they didn't do exactly what they set out to do.