Those What If? books were very disappointing for me. It seemed as though the academics who wrote them were more concerned with demonstrating their knowledge of wie es eigentlich gewesen than with speculation about how things could easily have been different, but when they did speculate about alternatives, the speculation was all over the map. Particularly egregiously, a lot of them failed to account for butterflies and so went on talking about, say, the exact same Constantini ruling Rome despite what appear to have been fairly major alterations three centuries before. It often seemed unclear whether the authors were supposed to be writing out-and-out fiction (either the drier sort that I write or more of an action story-type thing), vague speculation with no real basis in much of anything, more "hard-boiled" counterfactuals, or just talking about how important X event actually was because of how much different things could've been if it happened another way. This was kind of a mess.
The ones you listed do include some of the 'better' articles from those books, but some of them - especially that awful Hanson one - weren't. I thought that the OLYMPIC one was probably the best, which is kinda funny because the Tavern is loaded with people who steadfastly deny its premise.