Eriksen was important only in the second half of the season, but he wasn't the sole reason of winning of the scudetto. If you swap him with Hakan or another decent midfielder, the result would be the same.
Hakan was one of the reasons why we won the Coppa, Super Coppa and finished 1 point behind Milan, despite the loss of Conte, Lukaku, Hakimi and Eriksen. If Eriksen didn't have any heath issues and stayed, I'm not convinced that we would have won the scudetto.
And yes, Conte, Lukaku and Hakimi's title contribution is much bigger than Eriksen's.