It was originally chosen that Splatbooks would be small 15-20 page booklets to be used along Halo Mythic or a future standalone 100DOS Handbook. As of now, I've begun creating a standable version of 100DOS to be used with the various Splatbooks that will be made. This is including Medieval Times, which will be the first to show it off.
This means that Splatbooks will no longer need a second book to be used with, and will contain all needed rules and information for play. I hope this excites people, or at least people see this as a better move to make.
There are also many changes being made to simplify how the book flows for these Splatbooks. This change will eventually migrate back to Halo Mythic, when I have the time to do so.