Link had the carry mindset so far and less of the passive farm mentality.
The problem I think is that this is actually the opposite of what CLG needs now, despite it being what they needed before. This will be kind of lengthy, but I'd like to explain that.
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In LoL, the most successful professional teams typically have two of their three laners be super-strong players that make big flashy plays and outskill their opponents. The third player is almost always either a tank (if a top laner), someone that plays a lot of supportive mids, or an ADC that specializes in cleaning up after the fight instead of diving in and outplaying people. I'd list examples but then this would go on far too long.
In S4, what CLG had was a super carry ADC in Doublelift, and then Seraph was shaped into being a tanky/supportive top laner. To round this out, Link needed to be aggressive and a playmaker. This is the same kind of style that TSM has played for a while now, the reliable top laner, ADC that tries to make plays rather than playing safe, and mid that rolls people.
Again in S4, the problem was that this didn't work out so well. Sometimes Seraph would fail in his role to be the solid top laner and Double/Link would get blown up if they tried to be aggressive. Sometimes Seraph would be on a carry-type champion too and the triple-carry lineup historically either wins hard or loses hard which is kind of a gamble. Then other times, Link would be playing a supportive mid like Orianna or Zilean but there was no carry top, so the entire game would revolve around Doublelift as the sole carry (which again was risky and unreliable because it's not like he's Faker and can 1v9 or anything). What was the most effective for CLG was when Seraph played tanks, Double had a good game, and Link tried to be a playmaker, but that had two fail points where if either Link or Dexter played poorly Link couldn't get control and would fall behind.
Enter Zionspartan. Sure, he played Maokai at IEM, but we all know that at heart Zion is a carry top laner. I think now is when CLG should transition away from the expected tanky/supportive top laner (thus requiring a playmaker mid) and move more towards the carry top laner style that really hasn't been seen much in the pro scene because it's just been very rare to get a good carry top with a good ADC on the same team before (C9 runs a similar variant with Balls and Hai kind of trading off who gets to be the carry and Meteos is just good enough to adapt to that).
The wildcard here that we actually don't know about yet is Xmithie. Is he good enough now to actually enable Link to play carries? If he is, that would leave Link's own personal skill as the only deciding factor rather than a jungler having a bad game and practically getting 2v1'd all the time, and maybe if Link could work on that all of the time he'd get better at it.
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I think what we saw at IEM was that CLG as a team isn't good enough at playing together yet to have Link shifting roles all of the time, after all we saw how miserable he was on Orianna instead of the more assassin-type LeBlanc and Syndra. Ideally I think they'd run with Link as more supportive and give Zion the ball, but they could also decide to have Zion play tank a lot and Link carry more. What is clear though is that they need to play together as a team (with a real jungler) more to figure out how best to use Link and Zion and what roles each should fill. Then they should play like that for a while until they're working well together, because flip flopping in the middle of a series really didn't go well for them.