There was a really interesting article linked to from a thread on here a while ago about Kenny Stuart's training. I'm pretty sure he still holds the records for Ennerdale and Wansfell, so definitely fits the bill of excelling at the short and long stuff. I think he ran a pretty amazing road marathon time too. I don't remember much about the article, but I've a feeling he wasn't a "big" mileage trainer. Interesting comparrison with the likes of Billy Bland and Joss Naylor who according to legend just piled on the miles day after day over the fells.