The Devs apparently learned very little from the bad aspects of Eureka.

[Hysterior]

When I last checked, Pyros, Pagos and Anemos had 6-8 people in each instance. Not the 24 or 48 needed for these new fights.

Maybe server differences because on my server, Eureka at peak time is full.
I never played Eureka before and started about a month ago, now at Pyros and it is well-populated.