When Cheptegei broke the WR, maybe because few believed he could do it (I remember the discussion here and include myself), his last pacer dropped out not even halfway through the race.
And he ran the fastest laps alone.
Jakob could get pacing up to 3000 or 3200, exactly at WR pace or slightly faster, allowing him to “drop off” a bit once he's solo. I’m not sure what the most efficient way to structure that time trial would be.
He could get the record without necessarily hitting his peak shape (or Joshua's peak shape for that matter). And, personally, I wouldn’t raise an eyebrow: he’s earned the right to go for it under the best conditions he can set up, and at the end of the day, it’s still his legs that would have to cover 5000 meters in under 12:35.36
