Yep a fair point on the aeration given that there is no airstones in your design… though a decent flow in your return pump will turn each bucket over every five minutes and with enough flow it’s feasible that you could probable get away with areating just the res itself…
Typically this is the most common kind of layout .
What you have will work I think, there is always more than one way to skin a cat as they say… your design might just take a bit more bulkheads and plumbing…
It’s awesome to see this kind of thing DIY… props to you for having the motivation!