This was not said about the British but the Russian soldiers shortly before the battle of Tannenberg. However both officer corps were full of incompetent persons. Haig or von Rennenkampf are only a few example. The biggest moron IMO was not Haig but General Aitken who landed at Tanga. He could have achieved his objective to crush the German defense, if
1. he landed in Tanga and not several km south of it. There was a big mongrove jungle full of crocodiles and snakes- and a dam which now was a fortifcation.
2. he at once took Tanga and attacked the few Germans defending Tanga. But he had to land every thing on the ships, from gala uniforms to corned beef- without securing his landing area. So v. Lettow- Vorbeck was able to drive with new troops tp Tanga, but he was only able to form there a force of 1000 men with mostly outdated guns and a few MGs. Artillery was not available until the last day of the battle when two old guns arrived from Daressalam. Aitken on the other hand had 8000 men and the artillery of two cruiser.
3. he made reconnaissance patrols. Then he knew about the snipers in the trees and the fortifications. But he had to attack without any recon missions. So the British were trapped and at first attacked by a German company which suddenly appeared out of the jungle and frightended the British / Indian troops so that they flew at once back to the ocean. The brigadier gave the report he was attacked by 2000 Germans instead of the 200 in reality.
4. he made a core from his few good companies and form the 3rd rate troops around them instead of mixing. And he had to attack again without any scouts

. So they were trapped again. They had to fight against heavily fortified German MG nests as well as snipers- without artillery because Aitken denied the requests. Although loosing many men the British Elite soldiers were indeed able to take Tanga but the German counterstrike was so effective taht most of the Ghurkhas died in fights man to man. The German Askari fought there even with swords as well as the Ghurkhas. Nevertheless the British would have won the battle because the Germans had nearly no ammo left. But in this jungle were also bees which now were not very amused by the shootings and attacked the incoming British soldiers. So they again run into the sea. Aitken only saw his men waving and running away with crys of pain but without hearing shots. Now he gave the order to bombard the German positions but the grenades hit the German ambulance- full of wounded British soldiers- and the retreating British troops.
At the very end 78 Germans were dead but over 1600 British soldiers were dead or missing in the swamps.
This is one of the best examples for the British leadership quality of ww1. There are some other examples: Dardanelles, Jutland or Somme. Oh at Tange the Brits tried an invasion again- and were repelled again.

It seems to be they learned a lot

. Oh with the British equipment general Paul von Lettow- Vorbeck was able to give his troops new weapons. He got only three times supplies in the war: Twice via German blockade runners and once by the Brits.
Adler