You will get a lot more variability in small nurseries though, for that reason.
For example when you say about 'looking at individual situations', you are talking about individual staff and nurseries making decisions without so much behind them in terms of guidance and policies.
They might be really good decisions (unrestricted by beauracracy) - or in some cases, they might be really bad decisions (staff who don't know what they're doing).
You roll the dice a bit to be honest, but doing your research and going to look around helps a lot of course.
In a big chain, yes you might get a more 'generic' approach and they might be more middling quality because they might have more children. You might not get the super outstanding individualised care (but you might be surprised!) But the advantage is that, with the procedures and training that they have, you will hopefully avoid the 'really bad' end of small independents with less knowledgeable/ experienced staff making it up as they go along.
It can be a bit swings and roundabouts. If you go with a smaller independent nursery, do your research because it could be great or it could be awful. Whereas a big chain will almost definitely be a decent, safe nursery, if not spectacular.