No, Scottish independence wouldn't benefit England
One-third of the UK's geography would be lost, and the country would lose 8% of its people, which would have a significant effect on the UK's place in the world.
Scotland has traditionally played a larger role in the international presentation of the UK's image than its relatively small population would predict. Scottish items are a significant component of the British brand and play a significant role in the cultural impact of the UK; their loss would negatively impact that brand.