Fungal disease of Cherry trees

I have been asked to look at some poorly Wild cherries in the garden of a family friend. The leaves on said cherries have been "curling up and dying" - my first thought was bacterial canker but they had not seen any resin bleeding or oozing so I had to rethink that one. There are some 9-10 trees in their garden infected, with a small Rowan close up underneath one of the said trees also showing some signs of an infection. Some pictures here:

view of the whole tree:

It seems so far from the reading I have done around the web it is not bacterial canker or any environmental factors, such as poor drainage or soil conditions. The only thing I can seem to find which matches is something called leaf spot - link to RHS site here

The only advice for treatment of this condition seems to be to remove as much foliage as possible to reduce pathogen / inocculum levels and to possibly treat the tree with a copper fungicide to limit the spread of further infections.

Does anybody have experiences with this or similar diseases, and can you advise on the effectiveness of above treatments? Any advice or differing diagnoses much welcomed.

Below are some apple / fruit trees in the same garden which had some leaf curl and were otherwise exhibiting some signs of poor health. I wonder if this is caused by a similar disease, or overall weather conditions which have been very wet and warm this summer and most productive, I would imagine, for all fungal pathogens.

many thanks,

Luke