The quickest ways to earn guild coins is to participate in guild quest multiple times.This also depending on what the guild master/elder have selected for the daily quest.
Yes! Daily quest have to be manually activated by the guild master/elder.
So far in the daily guild quest selection, the best option will be “Try/Win xx time Pillage battle” or “Selecting guild mate as helper xx time” as this allow guild mates to attempt multiple times.
For example in the scenario above “Win in Pillage war 60 times”. If you are able to win 30 matches that will be 30 multiply by 5 guild coins which give you 150 guild coins.
Upon completing the guild quest, everyone in the guild will also receive 35 guild coins.
Assuming if you are able to farm 150+35=185 guild coins daily, it will only take you about 9 days to obtain a Anubis hero. 9 Days may seem like a long duration but if you a non-cash users, Anubis is a great hero to have.
Try to find out the time the guild master/elders usually activate the guild quest. Once the quest have been activated daily, rush and complete the quest.