Is there such a thing as too much ale?

Not at all. Our breweries have access to the best ale malt on the planet. I've had countless beermails from US homebrewers about how bland domestic American malt is and how their brews have been transformed using imported Maris Otter or Golden Promise.
Anyone who has had the same brew in cask and in bottle/can will have noticed an enhanced flavour profile.So to use high grade ingredients and let the flavours come out in cask does enable a low ABV beer to more than punch its weight.