Legion:
Tier 20 - 196 guilds https://www.wowprogress.com/pve/eu/c...ed-tarren-mill
Tier 19 - 571 guilds https://www.wowprogress.com/pve/eu/c.../rating.tier19
WoD:
Tier 18 - 350 guilds https://www.wowprogress.com/pve/eu/c.../rating.tier18
Tier 17 - 514 guilds https://www.wowprogress.com/pve/eu/c.../rating.tier17
Legion started with more players and ended up with less than WoD. Not entirely unexpected but still a disappointing result. Other realms have had it even worse, some suffering as much as 3x population decline.