Couts has a massive extension that costs around 8 mill. They decline

That's a big fat no from COL. As @Gmonwy said, Cotourier extension is way too much for COL to handle, and Newhook is primed to be the #2 center once Kadri is gone after this year.

You're asking for the equivalent of 4 firsts and a dman that is better than anything Philly can put on the ice right now for an overpaid guy with no return timetable and a guy who would be a great rental, but gives COL no future value.

Couturier is currently unmovable.
Giroux will fetch COL a good prospect, a first rounder, and a cap dump (in order to make his contract work).

My thoughts on it were you could get a 1C at 2mil for this year and then use him as a Kadri replacement who would be better/as good as Kadri and cheaper than what he’s going to demand. That’s if Couturier is healthy for the playoffs

The problem is Couts is signed at almost 8mil a year through 29/30, and I can't see Philly covering 50% of that contract all the way through. (coverage isn't just for this year, it's every year). COL needs to think long term as well as short term. A rental is great, and they could totally use Giroux this year at 50%, but they're only gonna give up a first and a b prospect for that (plus a cap dump off the roster).