Maybe we should talk about things in the order in which they happen.
ーLet's talk about things in chronological order.
「物事を時系列にして話しましょう」
in chronological order で「時系列順に・年代順に」
ーMaybe we should talk about things in the order in which they happen.
「物事を起こった順に話した方がいいかも」
in the order in which they happen で「(物事が)起こった順番に」
ご参考まで!