Xjyuk

Let us consider the sentence shown in the title of my post:

(1) He had to run faster than his tribemate, as the hindmost would be eaten by the lion.

(For context, watch this short commercial: https://www.youtube.com/watch?v=D-ie_aFsfb8 ).

I am at a loss as to how I can translate this sentence to Russian. I feel totally helpless. Below are my naive attempts.

(2) Ему надо было бежать быстрее соплеменника, так как отстающего съест лев.

I feel that "съест" is a bad choice because I never saw the future tense being used to describe past events. I guess that "съест" sounds as if the lion had not yet eaten anyone by the moment of speaking.

(3) Ему надо было бежать быстрее соплеменника, так как отстающего съел бы лев.

This sounds like a hypothetical thing, doesn't it? But it was the most real thing on earth. The hindmost was bound to be eaten by the lion. The lion was angry and hungry.

(4) Ему надо было бежать быстрее соплеменника, так как отстающего должен был съесть лев.

Here I tried to use the tricky verb "должен," being highly unsure how it fits here. I guess it sounds as if the lion had had been obliged, or owed it to someone, to eat the hindmost. Even if this construction works here, it is clearly not a universal solution, because the meaning of "должен" highly depends on the context.

(5) Ему надо было бежать быстрее соплеменника, так как отстающего съедал лев.

Here I tried to use a solution analogous to a phrase I had seen before: Он должен был побеждать, потому что проигравший вылетал из Высшей лиги. I had been explained that the form "вылетал" can be used as the future in the past. So I tried "съедал" here. But this form confuses me so much. I am very unsure. I do not even know how it is classified. And maybe "поедал" is a better choice, if there is a good solution of this kind at all.

My question is this: How will you translate Sentence (1) to Russian if I ask you to use a solution as universal as possible? I would also like to read comments on my hopeless attempts (2)-(5).

Ему пришлось бежать быстрее своего соплеменника, ибо оказавшемуся последним предстояло быть съеденным львом.

(3) Ему надо было бежать быстрее соплеменника, так как отстающего съел бы лев.

This option is good. "Would"is often translated as бы.

(5) Ему надо было бежать быстрее соплеменника, так как отстающего (обычно/как правило) съедал лев

This one is also correct, if you want to stress a habitual situation.

Должен isn't correct because it sounds like you wish to oblige the lion to eat the person.

Variant 3

(3) Ему надо было бежать быстрее соплеменника, так как отстающего съел
бы лев.

OR

Ему надо было бежать быстрее соплеменника, так как отстающего мог
съесть лев.

could (мог бы) and would (бы) are not exactly one and the same but in this context i think the difference is insignificant.

Variant 5

(5) Ему надо было бежать быстрее соплеменника, так как отстающего
съедал лев.

could also be correct if the narrative described how it usually would end up being or used to be.