Giroux is having a better season than Toffoli, and is an overall far better player than the new Flames member. The only thing that could cause a problem is the cap hit of the Flyers captain, at 8.2M$, but I'm pretty confident that Chuck Fletcher will retain some salary in order to facilitate a trade, considering Giroux will become an UFA at the end of the season. And Toffoli isn't a free agent at the end of the year.
Of course, a 1st round pick is a formality. You can add at least another draft pick (a 3rd rounder?), a roster player (a cap dump maybe?) already in the NHL and a prospect. Is it going to be an A-grade prospect ? I don't think so.
It's pretty sure that the Flyers will get a lot of assets for Giroux. Is it going to be more than what the Habs got for Toffoli ? Time will tell, but Fletcher will have to maximize the return in a Giroux trade.