I think you're intentionally skewing your roster evaluation to try and save your argument, and you misunderstand the state of the rebuild.
First, Rasmussen and Kubalik are very much middle 6 at this point and flirting, with fulltime top 6 roles.
Ras's move to wing was the best thing that ever happened to him, and he had a very quality top6 2nd half of the season. Unless Yzerman signs someone better for that role, Ras is probably our #1 LW going into the season.
Not sure if you recall, but sometime at the beginning of last season you and I argued about Kubs. I argued Kubs should never be in the top6 unless someone like Bertuzzi or Vrana are out (they were at that time) and you stuck up for Kubs being a legit middle 6 forward. You won that one, cause Kubs proved me wrong. His chemistry with Larkin and Perron is undeniable. I would gladly demote Raymond and Ras to the 2nd line with Copp to recapture that. Then he was one of the bests players in the tournament at worlds this year. This guys confidence is back in a big way since coming to Detroit.
Fabbri has played a middle 6 role (more often on the 2nd line) since being here and you know that.
Veleno and Zadina aren't bottom 6 forwards either... they should both be extra forwards, 13 & 14. They provide absolute nothing to the team besides the warmth of their flesh. I'd play Chiasson over both, and he's an extra forward. Luckily the Veleno and Zadina experiment is in its twilight at this point.
So the roster looks like this:
Ras - Larkin - Raymond
Kubalik - Copp - Perron
Fabbri - Kostin - Yamamotto
Berggren - _____ - ______
Veleno/Zadina
We cannot count on Kasper and Soderblom to make the roster at camp. IMO I think Kasper will, and Soder will not, but regardless you must plan like they won't. Prospects don't given spots, they have to steal/earn one.
Fabbri is also in questionable health with his knees. I'm not sure how much of him anyone expects next season.
Long story short - there are still plenty of openings on this team.
Personally, I like the physical defensive presence Kostin is going to bring, but I DO NOT want him as the regular 3C. I'm expecting SY to pull another Kubalik/Suter creative move to bring in a younger 3C that can both force Kostin down, and nip at Copp's heels.
Berggren probably ends up taking the injured Fabbri's 3LW spot and competes with Kubs and Ras for the top 6 roles.
Yamamotto is fine on the 3rd line, and can serve as the middle 6 when either Perron or Ray get injured.
The guy I kinda want for that open 4RW role is Garnet Hathaway. Bruins are letting him go. He and Kostin on the 4th would bring the violence this team has been lacking for years.
Sorry for pontificating, but lastly I think you misunderstand the state of the rebuild in Yzerman's mind. He hasn't sacrificed futures to bring in legit players yet, and he's still not. This Yamamotto/Kostin should be your canary in the coal mine for that. He's not at the stage where he's ready to sacrifice drafting ASP (and more) for Debrincat. He's going to find cheap creative options, create a thunderdome of competing for spots within the roster, and probably sell Perron and Kubs at the deadline this year. We're still doing the long plan.
I don't think SY will willingly hit the accelerator until this team makes the playoffs on their own. Once they accomplish that, he will seek to aid them, till then have fun waiting and growing while he provides the creative cheap options he can.
SY would probably disagree on some of my evaluation, but he also pulled the Yam/Kostin trade, and he's not infallible, but it was an absolute gift horse. I fail to see why anyone would question him on it. I liked Holland, but SY is a whole other level.