One thing that I do remember in one of the early Infinity issues is when Black Dwarf invaded Wakanda. Him and the Black Panther fought and if I remember correctly, Black Panther beat Black Dwarf with ease in which he had to retreat. But in this issue it takes the whole Galactic Council to defeat Black Dwarf. Fair to say that any member of the Galactic Council is easily stronger and more powerful then T'Challa, in which they should of been able to defeat Black Dwarf with even more ease then T'Challa. This didn't bother me at all, but it is something that I did remember and thought was kind of weird.
I had the same problem. Plus, right before that the completely street-level Shang Chi and Black Widow were able to defeat all his minions, who were presumably super-powered, and then Dwarf smacks Widow with his mace, and she gets up on the next page and fights like nothing happened.
It looked like Shang Chi had taken the beating between the two, so at least it wasn't so obvious. But yeah the probability of them two taking on Black Dwarf AND his minions doesn't seem logical. I also faced the same problem with Black Dwarf and BW. He smacks her across the room with his huge mace but then she's able to get up as if she's non human.