King Herald's Archers

It was the eve of the Battle of Hastings, and King Harold was inspecting the archers.
'Right, he said to Clive from Surrey. 'Show me what you can do with your longbow.'
'You see that almighty oak a hundred yards away?' said Clive from Surrey. 'You see that rook perched in its topmost branch? Watch this.'
He took a fine shaft from his quiver, took aim in a second, and loosed it. Sssssssssfth. A hundred yards away, the rook fell down dead with the arrow through its heart.
'Excellent! said Harold. Tomorrow you shall be in the front rank of the archers.' And he passed on to McTavish, one of his finest Scottish volunteers.
'Well, McTavish, said Harold. 'Are we as good north of the border?'
'You see that stile five hundred yards away?' said McTavish. 'You see that field mouse perched upon it? Watch this.'
In the twinkling of an eye a shaft was winging through the air, and three fields away the field mouse fell with an arrow through its heart.
'Excellent! said Harold. 'You shall be in the front row tomorrow, shoulder to shoulder with Clive.' And he passed on to Jimmy from Belfast, the only Ulsterman in his entire army.
'Well, Jimmy! said Harold, 'Are we as good across the water?'
Jimmy got to his feet.
'You see that barn door five yards away?' he said.
'I do/ said Harold.
'Watch this,' said Jimmy, struggling to get his arrow out of the quiver. A minute later, he took aim and loosed his shaft. It missed the barn door by half a mile and landed several hedges away.
'For God's sake, Jimmy,' said Harold, 'stay at the back tomorrow or you'll put somebody's eye out.