That's a pretty strained argument, to refer to Jakob's times at age 13 to make an argument he has speed. The comparison also with another runner is irrelevant - he isn't Jakob.
The only 400m time I am aware for Jakob is his listed pr, which is 51secs, achieved when he was 16. He will undoubtedly be faster now but I don't think it will be much. He will have added substantially to his endurance since then but speed is less amenable to large improvements.
There are several reasons why I think he lacks speed. If he was faster he would have recorded better 800 times than 1:46-47, and he would have been good enough to compete over the distance. He isn't - so he doesn't. Cram was a sub 1:43 runner over the 800 and is believed to have run at least 23s for the 200. He is undoubtedly faster than Jakob. Snell was a 22s runner for the 200 and a 1:44 runner over the 800 (on grass). Jakob is nowhere near that. Elliot ran 1:46x - the same as Jakob - on a dirt track. He was a 50s runner over the quarter. That I believe is closer to where Jakob is located. Nowhere near 48s.
The simple fact is if Jakob could run 22x for the 200 (and so 47-48 for the 400) he would be a world class 800/1500 runner, and not a 1500/5k runner.
But further to that, we see that Jakob doesn't have the speed of some of his 1500 competitors; if they are with him at the finish he can be outsprinted. His strength, so to speak, is his phenomenal endurance, not his speed.