Question for educators - combined classes(?)

Incognito because people may recognise me and I live in a small community! I live in a really rural place in the south west so small village schools are quite common. The one in our catchment is a bit old school with their teaching style (think opposite to gentle parenting) so I went to see another school that's nearby that's unsubscribed (there's 4 houses in their village and terrible parking). The school has about 40 pupils. There's like 2 kids in year 1, 6 in year 2 and few more higher numbers in years 3-6, reception and nursery. Apparently there year 6 test scores were excellent but I can't make sense of it on the government website(?) maybe because of the low number of pupils but there seems to be a huge range from below average to above average(?) Anyway they have to combine the classes and they mainly do this for 'topic' on a 4 year rolling curriculum and can combine up to 4 year groups when doing 'topic' (e.g. Romans, fire of London etc). They have TAs in every class and differentiate the work for different years. They also do maths and English in smaller groups (with teachers). They have excellent extra curricular provision as the PTA raises lots of money and they expect new parents to join this (which I would gladly do). The kids were amazing, autonomous, mature, respectful. There's free flow between all the play areas at break time. There's an allotment garden, forest school, animals, adventure playground, all weather pitch etc. Clearly the PTA fundraising has provided a lot of great things for the school. I'm so blown away by the school and it seems that despite their small numbers and class combining they have figured out a way to individualize the curriculum for each child. Am I being realistic here or do you think this could be disastrous?! Thanks for reading xx