Well King George V, as Head of the Armed Forces, was a German.... so that's a start.
'Jerries' was British army slang during the second world war for Germans. In the first world war, British soldiers were known as 'Tommies'.
No, St Lucia is part of the commonwealth, they recruit soldiers in the british army.
Duetsches Heer
The French and British
Yes, it had a large Army. This army was out-fought & then defeated by the German Army.
yes
Red Army.
The Americans, British, and The Soviet Union.
In World War I the British called the Germans Jerry/Jerries although it was more commonly used in world war II.
The British did not fight against the French in World War I. They were on the same side against the Germans.
The British army
British Expeditionary Force. This was the British Army which was stationed in France in 1939 and was trapped in and rescued from Dunkirk when the Germans overran France.