I'll start off by saying who definitively needs to stay:
- Bjergsen
- Hauntzer
- Biofrost
I think these three are the pillars of TSM atm and have carried team fights or at the very least are the most consistent. I believe they add the most value to the team.
As for Doublelift, I don't think he's bad. Mechanically he's proven to do well, however, he's had some issues with being caught out. He's not an incredible ADC either. If Doublelift was 80% as good at his role as the above three are at theirs, I feel like it wouldn't matter who was TSM's jungler because every lane would smash.
Which leads to my next point which is, because Doublelift is not as good at his role as Bjergsen, Hauntzer, and Bio are at theirs... Svenskeren as TSM's starting jungler needs to go. Fast. Fans of Svenskeren will try to say that he's not as bad as he seemed at worlds. The problem is that a lot of the same issues that people brought up about his Worlds play, were also present in his games throughout both 2017 splits and beyond. Sven is just not up to par with other NA junglers that didn't even qualify for Worlds. In fact, Sven was not just statistically the worst one of the worst junglers at Worlds, he's one of the worst in NA. I'm not saying that to trash the guy, because I think he's cool and obviously has built up some sort of chemistry with his team... It's sad to say it but if TSM wants to do better, they've got to cut him out...
and they need IWDominate... (lul).
no but they really do need to find another jungler. As for Parth, I don't know a ton about how he contributes to the team's success or failures.