Welsh Oak is said to be taller and more upward stretching.
The English Oak is said to be broader and spreads more.
However, how the tree grows has a lot to do with the density of its planting. A single tree in the middle of a field will stretch out sideways, its fellow in a dense wood with shoot up (slowly) to find the light!
Large, old, spreading oaks have a tendency to split their crowns, so heavy are their outward stretched arms so they have evolved to rest their lower branches on the ground. This can annoy some gardeners who worry that the weight of these will actually cause the crown to split and they are tempted to cut them off, often also in the name of aesthetics, tidiness and ease of mowing.
The head-gardener at Cholmondeley Castle knows how to treat his charges — this wonderful old fellow is starting to rest more of its weight on its elbows.
Another bugbear of mine is ploughing around oaks — those wonderful freestanding old trees in the middle of fields of wheat, oilseed rape or pasture — it is sad to see them stunted and struggling in areas where farmers plough right up to the trunks, disrupting the superficial rootlets and associated fungal hyphae. Farmers who understand their trees leave a good wide area around them undisturbed and you can see the difference.
These great solitary oaks can live for hundreds of years, providing homes for all sorts of creatures and shade for stock — they are worth nurturing!