I tend to think that we will either have all schools back full time or a full blown overwhelming NHS, pandemic on our hands by September. So I'm not sure you'll have much disparity between the hours they're at school.
You know the schools & you know the reasons they're at different schools, so what would you choose for them if both schools were open full time & what would you choose for them if no schools were physically open?
Our private school has been absolutely fabulous since even before lock down with communication, openness, 'live' teaching, feedback, activities etc. Cannot fault them (which makes a change, as I wouldn't have said that before all of this).
Yet the local schools, which friends kids go to, haven't been as good as I expected them to be, given how good they normally are.
You know your kids & the schools, only you can decide what's best, but I think you have to think hard about why they're all where they are in the first place. But move them, even if DS doesn't want to move if you think it's for the best.