[GranteedEV]

IMO a modern good line is as follows:

Forward A - Mobile speedy waterbug (Gaudreau / Czarnik / Frolik / Dube fit this)
Forward B - Size-ey scorer (Tkachuk / Monahan / Neal / Jankowski fit this the best)
Forward C - Responsible, mobile player (Backlund / Lindholm / Bennett / Ryan fit this the best

Not to oversimplify but good lines are probably going to have one player from each of these groups. And yeah, some players are going to overlap (Jankowski is arguably in category C, Bennett might actually be in category A or B) but in general, my point is this:

You need a bit of variety on a line to keep it dangerous. Loading players from one of the above categories up on one line is probably a doomed idea because it means you'll probably miss a player from another category.

So when you load up a Tkachuk-Backlund-Neal line, suddenly you're missing that waterbug player that Frolik and Czarnik have been. Of course there's more to it than that - ability to play a given forward position being paramount, but that's the crux of why I don't think this line works. Neal and Tkachuk are two very good players who are too similar.

On the other hand that's what makes 3M so effective.

it's not just 3M, either. Look at Sidney Crosby's line in recent years. On his left he's usually had a Czarnik type - whether Jake Guentzal or Conor Sheary. On his right he consistently had a Tkachuk type in Hornqvist. And he himself is the prototype center. Or look at another one of my favourite lines, Saad-Toews-Hossa. Again, Toews is a prototype center. Hossa, yes, was a massive body of a player, but what really stood out about him to me was always his speed. On the opposite side you had a guy in Saad who did a lot of the dirty work. It was a balanced line. And that's what Tkachuk-Backlund-Neal is not. And on the same note I think you run into the same issue with a Gaudreau-Monahan-Neal line. The balanced line appeared to be Gaudreau-Lindholm-Neal and they actually did score a goal together. The other balanced line appeared to Bennett-Backlund-Neal - I don't remember if they scored but they were pretty dangerous together as in this case Bennett moreso took on the waterbug role. And my preferred situation for Neal would be Czarnik-Bennett-Neal.

Or maybe I'm wrong and this is just a small sample size rearing its ugly head.