Walker had done all this so that everyone could unite in some way with the witches. Mostly because he knew that remaining focused on one thing would lead to them being bored. However, it was Ignus that he was most concerned with.
He knew that Remey would remain focused on the herbs and bring the three witches who took avian forms to the small garden being planted. They could share knowledge about the herbs and why they were used over the top of each rune formation.
The fact that they would most likely share this knowledge and also be giving knowledge to Remey so that she would be able to bring it back to Genesis was great. From this, they would begin the intermingling of alchemy and witch brewing.
All that was left from there would be the slow and steady testing that could come from those who learned both. Not that Remey wouldn't randomly find something in either interesting and bring it together in interesting ways.
