I’d much rather see Granlund back in the 1C role with a loaded line and give Celebrini fewer and softer minutes with consistent linemates to start.
We basically don't have a great 1st line, but we have a very solid 2nd line, and another solid 2nd line (if Celebrini can hang), and a strong 3rd line / weak 3rd 2nd line.
I'll plant my flag - based on everything we know and saw last year and in the offseason from Grier and Warsofsky, Granlund WILL center the first line (which is actually a good second line). It'll probably be the Lund line, but wingers might move up and down.
I think Celebrini is likely to center the second line with Toffoli and whoever cycles in on the left (my bet is on Kostin to start the season but I think it'll be a bit of a revolving door). This will be a decent 2nd line.
The Third line will almost certainly be centered by Wennberg to start, or
maybe Smith if he has a great camp with Wennberg and whoever else helping a lot on the defensive responsibilities. This will be a good third line and a weak 2nd line.
The fourth line will be a pretty good fourth line, no matter which players are rotating in or out.
All told, we will probably roll a lot more at evens (barring injuries) -- I could see 3rd line getting 15 minutes, 2nd line getting 17-18 minutes, 1st line 18-20 minutes, 4th line gets the rest (10-ish). might be even more balanced than that, actually.
That's my prediction and my preference.