وَلَا نُفْرِطُ فِي حُبِّ أَحَدٍ مِنْهُمْ
We do not go to extremes in love for any of them.
Ghulūw means taking affection beyond its proper limit. Praising one Companion by diminishing another is not a sound form of love.
The proper attitude unites honor with moderation. All Companions deserve respect for their association with the Prophet ﷺ; the rank of one must not be used to repudiate another.