I agree with the majority of this.
Ndiku fell, and Alamirew was disrupted by the fall enough to not be able to catch back on. So those two probably should be discounted. Everyone else was subject to a normal race.
Only area I somewhat disagree with is on degree of closeness. They were running about 13:20 pace leading up, or 64s laps. Farah closed in 54, meaning absolute no change of pace would result in a 10s gap. However, the pace actually begin to accelerate about 580m out, and resulted in a 62.8 penultimate lap, meaning 11s would be the margin for a guy that maintained his pace perfectly. 11.xx to be fair since Farah had the lead at the bell.
Now, if you can't kick at all, you probably don't have it in you to run any faster on that day. But I'd say if you're able to pick it up 2-3 seconds over the last lap, there was definitely some more in the tank. I'd give "unknown, but probable 13:0x status to guys within 7 or 8 seconds of Farah.
There is one confounder though, that likely favors the other direction, namely that guys have a tendency to shut it down once they are out of contention. In other words if Farah blasts away on 54s pace and all you have is 56s in you, there is a tendency to just cruise in from there and finish with a 6x even though you weren't desperately maxed.
I don't entirely disagree that some of the guys sometimes show up in questionable shape, but there can be many factors: just a really bad day, injury issues in training, travel related problems, etc. I think it's more unique that Farah doesn't have bad days, the closest I can remember being that loss to Soi when he said he was ill.
To me that suggests one of two possibilities: Farah and his support team have it fantastically dialed to ensure everything goes as well as possible leading into race day AND/OR Farah is fit enough that even on a pretty bad day he can be in the mix. I have no doubts the former plays a chunk of the role, but this is the main reason it wouldn't surprise me if Farah was capable of a 12:4x, even 12:4x low, type of time. To be clear I don't find it to be evidence supporting the notion Farah can run low 12:40s, but as I've said a few times it definitely does make me believe Farah is in at least 12:50 flat shape. It's incredibly hard for me to imagine a guy in the upper 12:50 ranges never, ever in 4 years having a race where they are more than 5-10s away from PR fitness on a given day.