Ethnos
Can you add cards to a band you already played in a Kingdom?
One forum reply reads the rules this way, and it matches the rulebook's wording that each band is laid down as its own group; no ruling is quoted.
- Brodie17 · Community · 2018-08-23
No. Each band is laid down as its own group in front of you, and you cannot add cards to, or replace, a band already on the table.