A few years ago, I did a little sketch of a combined US/UK military, based on the scenario of either the UK entering the US as states or the ungrateful colonials accepting the queen back, depending on your personal preferences. I basically ran into a wall trying to figure out how to merge the American and British regimental systems.
Let's compare the U.S. Army regimental system to the British one (line infantry only for now). The American system is superficially simpler but in practice much more complicated, which holds true for most transatlantic differences.
Unlike the British system, the U.S. regimental system has dynamic precedence, with a regiment's seniority ranked on a total number of points, awarded as follows:
- 5 points each regimental Presidential Unit Citation
- 4 points each regimental Valorous Unit Award
- 3 points each regimental Meritorious Unit Commendation, Navy Unit Commendation, and Air Force Outstanding Unit Award
- 2 points each regimental campaign
- 1 point each regimental Army Superior Unit Award and foreign unit decoration
- 1 point each year since initial organization
U.S. regiments have never been amalgamated and are activated and deactivated periodically, unlike British ones.
In the 1980's, as the U.S. tried adopting a more British-style regimental system, an American officer named Dwight Dickson suggested that the U.S. should amalgamate infantry regiments to create more distinguished individual regiments. His plan had 28 merged regiments.
When I made this spreadsheet, I noticed the 1970 British Army had 28 line infantry regiments.
I decided the 3rd Infantry Regiment (Old Guard) should be part of the Guards, junior to Grenadier, Coldstream, and Scots but senior to Irish and Welsh. That means one regiment had to merge. I folded the Argyll and Sutherland Highlanders into the Gordons (sorry).
I then lined the Dickson American regiments up based on the precedence of the senior regiment, based on a publication from 1997. The numbers would be different now, plus the amalgamated regiment should have a combined score, but simple is fine for now.
The numbers at the beginning are the two parent U.S. regiments:
7th/58th The Royal Scots (The Royal Regiment)
2nd/35th The Queen's Regiment
6th/46th The King's Own Royal Border Regiment
5th/36th The Royal Regiment of Fusiliers
23rd/39th The King's Regiment (Manchester and Liverpool)
1st/47th Royal Anglian Regiment
9th/31st The Devonshire and Dorset Regiment
4th/34th The Light Infantry
8th/48th The Prince of Wales's Own Regiment of Yorkshire
21st/32nd The Green Howards (Alexandra, Princess of Wales's Own Yorkshire Regiment)
16th/56th The Royal Highland Fusiliers (Princess Margaret's Own Glasgow and Ayrshire Regiment)
18th/60th The Cheshire Regiment
12th/62nd Royal Welsh Fusiliers
15th/50th Royal Regiment of Wales
14th/53rd The King's Own Scottish Borderers
17th/55th The Royal Irish
22nd/25th The Gloucestershire Regiment
20th/51st The Worcestershire and Sherwood Foresters
19th/87th Queen's Lancashire Regiment
10th/52nd The Duke of Wellington's Regiment (West Riding)
27th/327th The Royal Hampshire Regiment
13th/54th The Staffordshire Regiment (The Prince of Wales's)
28th/41st The Black Watch (Royal Highland Regiment)
26th/187th Royal Green Jackets
30th/38th The Duke of Edinburgh's Royal Regiment (Berkshire and Wiltshire)
11th/61st The Queen's Own Highlanders (Seaforth and Camerons)
29th/24th The Princess Louise's (Gordon, Argyll and Sutherland Highlanders)
This is entirely spitballed and probably not that interesting since the U.S. regiments don't have colorful names.
Just looking at the first one, the 7th U.S. Infantry is the "Cotton Balers" of Battle of New Orleans fame. Their finest moment on that battlefield came in a redoubt which was assaulted by the most successful British regiment of the battle, the 93rd (Gordon) Highlanders. That suggests the 7th should be amalgamated with the Gordon, Argyll, and Sutherland Highlanders. There were very few clashes between American and British regulars in the War of 1812, so this system of association won't work for everything.