I'm actually surprised there's so many people who don't understand/are critiquing Grier for this.
He literally needed to spend money. This is a familiar player, that has won 2 cups, been to another SCF, and another ECF since leaving the Sharks in 2020. We're not acquiring him to score 20 goals...he's there to insulate the team that just came 32nd in the NHL, and is bringing in 18 year old Celebrini and 19 year old Smith, amongst other U23 players. Casual SJ fans will remember him from his past on the team, and he's probably going to end up with a letter on his jersey. Those are all important things for the team with the lowest attendance in the NHL, and who's captain may never play again. Grier got hired out of the Rangers org, so of course he has buddies in hockey ops he's willing to help out...they literally helped him become a GM in the NHL.
There is nothing surprising about this move at all. It's literally the exact same as overpaying for some bottom-6 useless plug in free agency except they wouldn't apply to all of the factors I listed above.