That's putting a lot of pressure on that top pairing, especially with Rielly having to play his offside, which he has yet to do consistently in his career. Our PK is also still going to take a major hit, with Hainsey and Zaitsev combining for ~450 tough PK minutes.
TBH, with the types of roles guys like Rielly, Dermott and even Rosen would be getting, I don't think Miller is a good fit for this team. We already have those more offensive-minded two-way guys. We need guys who can handle heavy defensive minutes but still compliment a skilled player. We need another guy who can compliment Rielly and share heavy PK minutes with Muzzin. Then you can have Pysyk as your main 3rd PKer with Dermott and Rielly being your 4th/5th PKers (Rielly mostly so his ice time is not wasted PKing a ridiculous amount of the time). Rosen gets in if necessary, since he can PK, but we can take him up slowly. Miller, at best, is a #5 PKer on a contender so you are lacking that other high end PKer to put with Muzzin.
Ironically, we need a better version of what Zaitsev was last year. Or even a better Hainsey would be fine (i.e. like a RD Muzzin or maybe a guy like Pesce). Miller is far from that. He's essentially a Dermott, but more offensive minded.