This is something that actually escapes a lot of fan's radar I feel like but yes Sawamura is a ridiculous prodigy. He isn't gifted in terms of strength/velocity like Furuya but he's incredibly gifted in other fields, many of which other don't have. Sawamura practicallyl haven't been properly trained until he enrolled into Seidou and he's only started playing and practicing baseball "seriously" for a better part of one year, even Furuya was trained somewhat more extensively by his grandpa or his middle school before he stopped playing. Sawamura's ability to create a Cutter by pure accident is a skill that's extremely rare even amongst pitchers. On top of that, Sawamura's flexibility helps him injects a huge amount of spins on his pitch which makes it rises at the plate and looks sharper than a similar pitch of the same velocity, this allows Sawamura to get strikeouts despite his lower velocity and has became sort of a deceptive power pitcher as he could rake up as much as 8 strikeouts through 5 innings. His unique form is actually something that many pitchers are taught but are unable to do, it requires a lot of flexibility for a pitcher to be able to hide his pitching arm behind the head like that and due to that hidden arm action, Sawamura pitching delivery is always on time and has a good rhythm, allowing him to repeat his pitching mechanics consistently which as a result producing consistently good pitches and consistently good performances. He acquired all of these in a span of 1 year, you cannot be a scrub and acheive this even with extra amount of efforts, it's when both talent and efforts are combined that a player would bloom.
Sawamura is quite a complete package compare to Furuya who has the only thing Sawamura lacks, the power aspect; however, there are many facets to pitching; namely control, pitch movement, change of speed and velocity and Sawamura has all of these beside velocity. It's unfortunate that many uses Furuya as a benchmark to compare Sawamura with and they seems to think Sawamura is not as good as Furuya because he lacks that one aspect of pitching but it cannot be further from the truth.