Well Hansen minus the Sedins is not really an every-day top 6 forward so I'm reluctant to include him. Baertschi is fair and I only left him off because he didn't cement himself as a surefire top 6 F the way Hutton did as a top 4 D.
For the moment McCann and Virtanen are still legit question marks though I am hopeful both of them will get there. Tryamkin is probably comparable to these two but I feel he showed more in the KHL and his short NHL stint than the two 19 year olds.
Also it's not right to compare raw numbers. You need 50% more forwards (6) than defense (4) in these top 6/4 discussions. So in terms of raw numbers you need 2 extra forwards anyway.
I think it's debatable if the more pressing need is at F or D (personally I think it's at F) but that still supports a BPA strategy, rather than a positional focus.
Again, I agree with your actual sentiment about picking BPA, defensive need being over-prioritized/overstated, and that we have a massive need for top 1st line forwards (I disagree that top six forwards is the concern though), but I think the way you framed it initially was a bit disingenuous.
It's undeniable that even proportional to how many you need in each position, our defensive prospect depth is currently far weaker than our forward prospect depth.
The only young D we have right now who has the inside track on potentially being a core player is really just Hutton on an island by himself. Tryamkin is a nice story who can possibly sneak his way into the bare-minimum of that criteria if everything goes right for him and he surprises even more than he already has, and Subban/Stecher is a total longshot that we can't count on/pencil in in any capacity as well (to even make the NHL, period). We pretty much have noone behind those guys.
Horvat and Boeser, I would argue have as much potential/project just as well as Hutton does. But in addition to that, Baertschi and McCann, for the time being reliably project onto those roles. Virtanen is hit or miss, but will probably at least be a core third liner and very possibly be a bottom-end core top-sixer. That's five guys who at least look alright as a starting point that, one (or two) additional big pieces can conceivably complete.
If you hypothetically add Matthews to the mix, it's conceivable and perfectly within the realm of possibility that they've landed on the right group. I don't think the same argument can be made for adding Ekblad to our D pool.
Baertschi - Matthews - Boeser
McCann - Horvat - Virtanen
I would argue that Hansen is, at this point, a legitimate top six winger without the Sedins, especially given the current standards of the NHL. At the very least, he is a top-end 3rd liner with a game elevated to a degree that is every bit as important as a top six winger. I also think that Gaunce has a better chance of possibly turning into something than Subban/Stecher do.
Defense is still a far far cry from that. Even considering the ratio that you need, even being conservative, I think it's currently something closer to 3:1 in favor of our forward prospects rather than the 3:2 that you're suggesting would be ideal.
That said, I still agree with you that BPA is the way to go because the forward class is far superior to the D class, none of the defensive prospects are reliable/safe projections into that role, and Ds are easier to get in later rounds, and I personally believe that a #1 center that we don't currently have is an absolute prerequisite whereas a #1 defenseman may not be. I'm more comfortable contending with a "defense by committee w/ help from goaltending/coaching" group rather than a "scoring by committee without any star offensive players" group.
Given the choices, picking a forward is the obvious choice. However, I would say that if the choice is between a forward that we know for a fact is going to be a bottom end top sixer with zero 1st line potential vs. a bottom end top four defenseman with zero 1st pairing potential, I would go with the defenseman.