Just to make things a little easier.
The half marathon times seem to make little sense compared to the marathon times. A 1:23 is an absolute walk in the park effort wise compared to a 2:55. And the 1:21/2:53 one is also way silly. .
I was (happily) thinking the same thing. I can (and have) put down a 1:23 without killing myself. I’ve not (yet) run sub 3.