You/ve noticed that when I refer to Early or Late Blight I almost always say Early Blight ( A.solani) and Late Blight ( P.infestans) so I don't think it makes any difference what one calls them as long as it's understood that it's two very different pathogens that cause the diseases.
Do you folks call Early Blight Alternaria?
Alex, just go to Google or even go to the Problem Solver here at Tville in the Disease Forum and you'll see that the symptoms of both are very very different.
Early Blight leads to primarily spots on the leaves that are quite distinctive and less often there can be fruit symptoms and stem ones as well. If this fungal disease isn't prevented there's defoliation of the plant but not death of the plant in a short time as one sees with Late Blight.
With Late BLight one of the earliest symptoms is bending down of the petioles and then greyish water soaked looking spots on the foliage, and as I said before, plants can be a stinking mass of black tissue very rapidly.
One of the problems here in the US is that folks use the word blight to describe anything wrong with their tomato plants and that leads to sometimes lots of questions that I or others ask in order to make some kind of diagnosis of what really is wrong with the plants.