Thanks. Indeed, both RKB and SD are realistic for basketball anime. But then, basketball has evolved in the past 2 decades that new playbooks and tactics have been discovered and used, and player positions have become more defined and combined together.
RKB gives us those updates while still introducing the readers and viewers into basketball without that weird exposition every episode because people are more interested with the story rather than its more serious basketball side.
With the LNs coming out, I hope Keishin could finally participate in tournament play. That way, we can see how does the 4-1 offense fare in TP. Of course, Subaru can vary their playbook depending on the situation. For example, he can field in Kagetsu as PF to eliminate a disadvantageous mismatch in that position.
They are surprisingly similar, but while SD is more about the growth of Sakuragi and everyone else are already really good in RKB everyone gets to grow and learn new skills which makes it more dynamic as each girl gets their share of sport light, even Tomoka is not flawless and has room to grow as a sports player, so IMO it's just more interesting and you get to appreciate the different skill sets for the different characters and their position. Also RKB's basketball is not as flashy and never over the top, even though SD is already fairly realistic for the sports genre there's still the problem that everyone is like a pro NBA player even though they are only high school students.