They're beautiful and look well fed. You did a great thing in adopting and caring for so many of them. Lucky cats, especially to live in your glorious garden!
Sadly a lot of the cats we get in France are desperately thin and clearly in poor health when they first arrive. A couple of years ago there was a youngish female cat who reached the point where she liked me to stroke her, and when she fell ill I put her in a cat carrier and took her to a local vet. I warned the vet that the cat was feral and the vet assured me that she was well used to treating ferals. Unfortunately as soon as the cat was scruffed she freaked out and shredded the vet's arms... Perhaps some vets are also more intelligent than others?
There's a chemist who lets me have antibiotics (made for children) very cheaply and without a prescription, so now I try that when they get ill - if it's cat flu or an abscess and I catch it early, they usually recover, but there's a lot of feline AIDs in the area and some don't make it. But at least we try to make sure they have food