We will never be comfortably defensively until we upgrade our back line. That is with or without Kante in the side. Liverpool play with no real defensive minded midfielder?
In terms of balance, I think it's pretty pretty evident that a midfield of Mount/Jorginho/Kovacic provided us everything we needed in midfield, particularly on a technical aspect. We have a holder, an attacker, and an aggressive dribbler. Kante only really comes into play when we are against sides that either have a better midfield than us or against sides that have a better attack. Other than that he has no real use in the starting XI.