Helion never proof read anything. They will publish pretty much anything. There is no quality control in terms of content.
On the other hand they have published some great books, their production values are good and so is their customer service.
It is wise to look out for authors you know and like and for reviews.
Yes, I agree. I have the Commotion Time book by them, which is good. You might like it, as I know you’re into the early 16th century. It’s about the various Tudor Rebellions, or perhaps focused on only one of them, I can’t remember.
If the ones you mentioned are good then I might get them at some point. I spend ages reading reviews of Osprey books too before buying them as I know they are quite variable as well!