circumstances like those related to the person the speaker is addressing
そういうことでは
a thing like this
そうありそうなことだ
That's about it, I should say.
そういうわけさ
Everybody knows that.
the condition of [being logical supposed to]
こういうわけさ
(理由を述べるのなら)―This is how it is―(物語を叙するのなら)―This is how it happened.