England football shirts will always sell, it doesn't matter what Umbro do to them. I only have to refer back to the Grey Euro 96 top to prove my point. You can say it looked good with jeans all you like, but it was a horrid fashion mistake.
Why exactly Sunderland changed their football shirts this season I don't know. The shirt is very similar to last season's effort and if I was a Sunderland fan, I'd be wanting slightly more effort.