Yes...but...we do have two #1 RD. They don't often play like it but by most accounts, Letang and EK are #1 dmen. If you have them, you just need a complimentary partner that is "good enough". Pettersson is by no means a #1dman but he's a hell of a top pairing dman for EK or Letang. Same way Dumoulin was. I don't think anyone considered him a #1LD.
As long as you have a competent partner that is "good enough", that's good enough. Jan Rutta was Hedman's top pairing partner in their first cup run.
The ideal situation is to run Petts-EK as your top pairing and then POJ-Letang as your 2nd, and then Graves-JSI or whoever for the 3rd. This is baring any trades or UFA signings. Certainly wouldn't hurt my feeling to sign a 2nd pairing LD for Letang and trade POJ out for a forward.
I think Dubas built the team that Mike Sullivan wanted. WIth a lack of success, I do think he'll pivot. Post TDL, we're in this dead zone where not much is happening. Everyone is waiting for the SCF to be over, the cap to reset, and getting ready for the draft. So a lack of moves at the moment doesn't mean there isn't internal decisions being made. I think he's been clear too - he wants young players and draft picks. That's what he said he wanted in the Guentzel return too and that's what he got.
The telling part will be FA for me. If they sign 2-3 30+yo guys as depth guys (like another set of Eller and Acciari) then I'll throw my hands up like everyone else. I think you'll see Smith, POJ, and possibly Jarry being sent out for picks and prospects. Maybe not top notch ones but at least something to have in the system in addition to the cap space.
If you can send Smith out for a 4th and trade POJ for an equal forward - say Grundstrom, Max Jones, Kaliyev, Yamamoto, Dorofeyev, Berggren, etc and commit yourself to inserting young guys into the roster - Poulin, Puustinen, the trade forward, and potentially one or more of Gruden, Kouivunen, Yager, or Broz, it also positions us to take on a bad contract from a cash strapped team with a sweetener. Like, could we get Carolina to give us Jack Drury if we take Kuznetsov? Ryan Johansen or Petersen? Campbell? Gavrikov? You get a good young player or a 2nd or even a 1st from a couple of those, that could help restock as well in the pursuit of rebuilding the young talent pool.