Faction + Commander Name: UKF Hammer Assault Regiment
Theme: The Canadians, Scots and Irishmen were always known as the Commonwealth's "shock troops", since the bloody trench warfare of World War 1 up to the battlefields of World War 2. Using American equipment together with trained men from the Colonies and British support as well as tactics are a sure recipe for victory.
Unit and Ability Roster
Slot 1: Assault "Tommy" Section/Scottish Infantry Section
4 or 5 man squad armed with American M1A1 Thompson SMGs and equipped with No. 77 WP Grenades as per RoastinGhost and others' suggestions. Ideal mobile infantry squad meant for urban close quarter fighting as well as spearheading infantry assaults. Crecer13 also suggested an armor upgrade for them but I'll leave that up to the balance team. Alternatively as Stark suggested they could be a normal Infantry Section using the Commando/Sniper voice lines and having no cover penalty as well as not being able to build trenches and caches for example. They would also have the "Assault" package which would give them the WP grenades and Thompsons and the "Recon" package which would give them the camo and "snipe" abilities. A versatile mainline replacement unit in which you can decide and choose in what to invest, balance will again be ultimately left to the community dev team.
Slot 2: M1 81mm Mortar team or ML 4.2 Inch Mortar team
Mobile mortar team meant to support infantry attacks with close indirect fire, perfect for clearing out enemy garrisons and MGs as well as providing friendly infantry with smoke cover where needed on the battlefield.
The ML 4.2 Inch Mortar is per again RoastinGhost's suggestion, I don't really mind either one.
Slot 3: Vehicle Crew repairs
LoopDloop suggested that I replace the Hold the Line ability as it's not working properly with something a bit more practical, especially when combined with the Achilles. Other than that I had an idea of adding the Air Supply Operation so it's possible to have a choice between a smaller and faster mortar and an AT gun drop or a bigger and slower more powerful mortar like the ML 4.2 Inch Mortar which can then be chosen. Ultimately I will leave the decision on these abilities up to the balance team as they probably know what's better than me, I'm just here to suggest some new ideas.
Slot 4: 3-inch M10 "Achilles" Tank Destroyer
Commonwealth variant of the American M10 Tank Destroyer, provides a cheaper and earlier coming alternative to the expensive and slow Firefly.
Slot 5: Strafing Support
Call in the Flyboys, the Royal Air Force stands by for strafing support, from the Vanguard Operations Regiment.
Strategies and Rational
I have always felt that the Colonies were under-presented in CoH2 because there were a lot more Canadian-esque units in CoH like the Canadian Infantry section found in the British Campaign, the M7 Priest as well as the 25 pounder also had Canadian voiced crews. Apart from that, the British are lacking mobile assault close quarter infantry apart from the Commandos, mobile indirect fire that doesn't cost fuel like the Land Mattress and a less expensive and more mobile tank destroyer.
Here's a funny little picture I took from the All Units Mod a long time ago which pretty much sums up my idea, minus the infantry unit and the other abilities: