Mirroring columns to existing columns

I have created several boards that have some of the same columns. I would like to update the main board and have the changes go to each sub-board. I understand the mirror concept, but is there an easier way? When you create an item in a board based on an automation it gives you a list of the current columns with the option to match up the same columns in the other board. When setting up the mirror column all new coumns are created instead of using the existing columns. Is there a way to mirror the columns without creating a new one?