I cannot speak for other guilds, but we encourage our guild members to not fill all the gaps until everyone has met any feat requirements. Some times we get carried away, I have on several occasions. But usually that only happens when we are getting close to the cut off time. We even reserve the back wall for weaker guild members. It puts pressure on us to make the first three columns as strong as we can. But those reserved places allow everyone to, when it works, the chance to satisfy the requirements. As others have said, your Guild leader can use the chat and commands to let everyone know that they need to be considerate.