Connecting dots that you've fabricated in an effort to paint a baseless claim into fact...
Kreider and Stepan had success with both Zuccarello and St. Louis as well as Nash.
Nash also happened to be with Kreider and Stepan during the career-worst slump/funk he was in for the last 2 months of the year (May and June). I find it interesting that you neglected to mention that part of it.
The bottom line is that Kreider&Stepan are a unit, Brassard&Zuccarello are a unit, and Hagelin&Stempniak have a good chance at flanking whomever wins the 3C spot, because of the remaining wingers, they are the two most ideal 3rd-liners, as they have proved that they are capable of smart two-way hockey while contributing scoring depth in that role, and with the minutes associated with it.
That leaves Nash and St. Louis as the remaining top-6 wingers to slot in. Since St. Louis and Zuccarello are both tiny (despite neither one playing a small game), the obvious move is to keep them on separate lines. Thus, we have:
Kreider Stepan St. Louis
Nash Brassard Zuccarello
Hagelin Miller Stempniak
and The Dominic Moore Show
Easing the transition even more is the fact that Nash is taking Pouliot's spot: Nash has the same body-type and somewhat similar skating stride while being a lot better at every offensive aspect of the game.
Fitzy helps further echo these sentiments as he eloquently articulates below:
All of Nash, Zucarello, and MSL should be separated.
They're all playmaking wingers. They should all be able to handle their own line.
You can also look as to what Vigneault prefers to do... which is to separate the playmaking talent. He only put MSL and Nash together because he had no other alternative that late in the season. The Rangers were in a playoff push, he did the safest thing he could do and combine the talent until Kreider could come back.
I haven't seen AV put a prospect in a position to fail yet, as the coach of the Rangers. There were several times where he had to evaluate the skill set of several young players and thus put them in different situations... but afterwards he surrounded them with players that would help them succeed.
Helping players succeed helps achieve the main goal, which is helping the team succeed.
I doubt Miller would have even been yo-yo'ed the way he was last year if we had slightly more AHL depth. Sather must not have liked doing that to JT, he over compensated with his offseason agenda by signing more AHL depth than was necessary.
AV with prospects?
Kreider on 1st line surrounded by our best center and our most dynamic playmaking winger (at the start of the season).
J Moore paired with Kevin Klein to stabilize his erratic playing.
Del Zotto moved to more comfortable side once he expressed lack of confidence.
Fast was evaluated for first 5 games of season. 2nd stint with Richards and Hagelin.
Zucc with Kreider, Stepan... then Brassard to help get Brass going, too.
Hagelin-Miller-Stempniak wouldn't be putting Miller in a position to succeed. It wouldn't be putting the team in a position to succeed.
Balance the lines. That's what I wanted when AV came in. That's what he did.
Miller will be on the 2nd line, in between either Nash or MSL and Hagelin.
He'll get 13-16 minutes a game, and when it gets late in the game, or we need to play more defensively, D. Moore will take his spot centering the 2nd line.
Nothing else will happen barring injuries and underperforming play from Brassard or Nash or MSL or Kreider.