I mean that:

Cohort
Upon reaching 6th level, an enchanter using this variant gains the service of a loyal cohort of the player's choice (with the game master's approval). The cohort is a 4th-level character when first gained; after that point, follow the normal rules described in the Leadership feat to determine the cohort's level, but treat the enchanter's level as being two lower than normal.

The enchanter doesn't gain any followers from this ability. If the enchanter selects the Leadership feat, he attracts followers as normal, the penalty to the enchanter's effective level is eliminated, and the enchanter automatically qualifies for the "special power" modifier to his Leadership score.

An enchanter using this variant permanently gives up the ability to obtain a familiar.

Is that mean to determining cohort's level you use all class level or only enchanter's levels?