I think by this point, we could remove the reincarnation trope, and it'd be exactly the same, granted the children would need to be pretty smart for their age, but that's not exactly uncommon in manga/manhwa these day. It'd also make it less frustrating from the viewpoint of a reader, because smart children are still children, and not "adults" possessing child-like bodies.
\(ಠ▃ಠ)/