I actually think the British military leadership did reasonably well, if not better than most. They certainly took a great deal of care in the wellfare of their troops in the periods between attacks, far better than any of the other major nations. The manpower of Imperial Germany and Britain and the Commonwealth did quite well, though the boorish leadership of the british was a big let down.
It also must be remembered that the very small British and Commonwealth armies were built up to a massive size in a very short space of time, a lot of their commanders were as inexperienced as their troops.