Ash trees doing it differently

Here is a photo of 3 ash trees, the right hand two are in my neighbours' garden and the left hand one is in the garden next door to them. (There is also another one behind the third tree).

I hope it is clear that the middle tree is nearly fully in leaf and the side two are only just starting to come into leaf. One year my neighbour and I noticed that the tree near the fence between us looked as if it was struggling to keep going. I didn't say anything, but I was rather hoping it would die as I am worried about shade, especially as the trees are still relatively young - and small. But next year it was looking all healthy, and another tree was slow to leaf and was much less leafy when it was in leaf. Also each year one tree doesn't have many ash keys. Beech trees have their "mast" years where all the beeches in an area have loads of seeds (nuts?) and other years hardly any. Other trees are supposed to have a similar pattern, just so extreme. But it seems these ash trees don't read the right books! My neighbours who have liked the trees for the privacy they give them are beginning to be worried by the shade, but it is the tree in their neighbour's garden which gives the most shade to their garden. However, I live in hope that they will get the chop as I don't get any evening sun in garden.