Hello,
My apologies, sometimes the posts get buried very quickly.
When you are planting guides in Edit Guides with the Plant Guides tool, you can enable Adopt Guide Shape in the tool options window. This will not only make the newly planted guides a copy of the selected guide, but will also inherit the same strand group. For now this is the only way to create guides with pre-defined strand groups.
Jeordanis Figuereo (Product Designer. EPHERE Inc.)