Why does the future tense I come AFTER the future perfect on a timeline?

We all know these tenses from German, but why does the future perfect tense (e.g., "I will have eaten") come before the future perfect tense (e.g., "I will eat")? If you had a fictional timeline and identified a point in the future where you would eat, you would first eat and then have eaten, or…

which tense in the main and subordinate clause?

Can someone make me a list like this: main clause. subordinate clause e.g. present tense, if? praeteritum. because? future1, because? pluperfect, because? perfect because? future 2, because? I know which tense always comes, and I need the right ones. The question marks are for the tense. 🙏🏻 I always know what's coming in the subordinate…