Uo and Ua were both used depending on the region of Munster (Brian Boru actually appears on rolls with both variants when he was younger; he didn't start using his father's name until shortly before his brother died). However, Ireland's rebels would still have mac/uo variants. A few variations, if it could be done, would be nice for rebel leaders in Ireland, since mac variants were used in Ireland too, but we will invariably need to make exceptions unless some one is particularly dedicated to making names work appropriately (which, if one wanted it perfectly accurate, some would have to be 'named' after their grandfathers, or have their names change during the course of their lives).