The way I see it:
Kovalev is one step away from becoming a star. One fight. But there is only one fighter that could serve as that. Adonis Stevenson. I don't think Andre Ward can provide Kovalev stardom if SK was to win, primarily because the argument would always exist that Ward wasn't a true 175 pounder and wasn't legitimate competition, if he is to lose.
Golovkin is two steps away from becoming a star. Two fights. The first of which is David Lemieux, which is taking place in October and will serve to be his first paper view fight. For Kovalev, this fight was Hopkins in AC. My friend was part of the video crew for that fight, it wasn't made into PPV because they recognized it's demand too late and didn't have enough time to promote it. So they put it on HBO for free. If Golovkin beats Lemieux, he is 1 fight away from reaching stardom, and that can come in the form of 3 boxers: Canelo, Cotto, or Mayweather. One of Mayweather's managers came out today and said they're not billing this fight as if it was going to be Mayweather's last fight. "It is his last fight. With certainty". Let's take that for face value, which I don't but whatever... Floyd is out. Winner of Cotto/Canelo is next. Did either sign the clause that forces the winner to fight Golovkin next? If so, Golovkin has his path. And is much closer to achieving stardom than Kovalev is, considering Adonis is choosing to stay away from him.
Ward is three steps away from becoming a star, again. He rose to prominence in the tournament he fought in back in 2011. That was a long time ago. He fell off a cliff. Now that division is barren from talent. 168 isn't what it used to be. You have Dirrell, who looked horrible against DeGale, and the two are best friends - so that's not happening. Ward fought at a different weight class just so he wouldn't have to fight AD back in the olympics. DeGale? His name isn't star level. He holds a belt. That's step one. Then a mandatory. Then one of Golovkin/Kovalev. Or. He can hit a shortcut and one of Golovkin/Kovalev will bight before it is Ward's actual time to contend vs. them. He is 3 steps away but the possibility of a shortcut through one of them exists. If he beats either, he reaches that level.
Beating Ward doesn't give stardom to Kovalev but does if Ward beats him. Same with Golovkin.
Golovkin is going a different path. Him and Ward are slated to meet in mid-late '16. Golovkin has 2-3 more years of excellence. Maybe less. He's going to have to bunch up his fights in the next 2, let's say. Lemieux in Oct. Johnson in Feb. Canelo/Cotto in May/June. Ward in September. Mandatory in January/February. Kovalev in May/June/July '17. Depending on the outlook, that's about it. He'll be 35 by the time he would potentially do that Kovalev fight. He fought in amateurs for too long. 33 is his prime. Maybe also 34. And maybe 1 or 2 huge fights @35. Every boxer is different, but there is only 1 Hopkins. Most other guys that dole out punishment die by the sword once they get up their age.