Be reasonable. One player doesn't take a team from being 0-13'd to literally the best in the world. Demon1 was a huge reason of why they made their run but the entire team as a collection (and individually) improved a significant amount. Potter, C0m, Jawgemo and whatever else they throw together can't be expected to be world beaters (especially with little to no support staff which seems to be the case because EG lol) BUT, there's just no way anyone can believe they'll suddenly be an F tier team.
Top of C, low B is realistically where things should land if any imagined roster doesn't over/under-perform.