>>3797481A lot of earlier colonial wars had that problem, the British were more used to fighting European wars where there were set rules and traditions rather than guerrilla wars like the American revolution and the Boer wars. The British army wasn't really much of anything till the world wars, excluding the navy of course.
Interesting considering the size of the empire, although large British companies like the east India company had massive private armies that made up for the shortcomings of the regulars.