I have an ancestor of mine, John Butler, who was a a Lieutenant in the Wicklow Militia he was an Ensign in 1798 and made Lieutenant in 1800, I have a later document in which he states he shed blood for King and Country. I think he must have left the Wicklow Militia shortly after 1800 as he was married in 1802 and set up his law practice in Athy.
I also have another relative Thomas Butler from the Wicklow area who served in the Dublin Militia, where he became a Captain, when he left the Militia, in around 1818, he stayed with a William Butler of Whitehall House near Baltinglass, I have letters Thomas wrote from that location.
I know that the William Butler of Whitehall House died in 1844 so its quite possible that William Butler of Whitehall House is the same William Butler who served as adjutant in the Wicklow Militia.
William Butler, the adjutant, appears to have served in 27 regiment of Foot (Inniskilling) he was Ensign in 1804, Lieutenant in 1805 and Captain in 1812, he was placed on half pay 1817.
I suppose that Richard Butler, the other adjutant, may also be related to William and Thomas, perhaps a younger brother, Richard appears to have been in the 91st foot an ensign in 1812, Lieutenant in 1814 and on half pay 1816.
Still lots of research to do