I agree, but you can't argue that they didn't also try to make them look similar to the originals where possible?
Why can't one argue this? Look in Bahto's book at the early pictures of NGLA. The features do not look anything like they do now.
If not, then why are most of these holes visually obvious upon first seeing them as to their sources?
Because most of them were built by Raynor or Banks, who had very recognizable styles, and did not stray very far away from their Master's basic concepts.
Or, could it be that it's because they all built courses with a preponderance of template holes?
I also have Uncle George's book and while the features weren't as crisp as they later evolved into, the shaping and location of the features on holes such as the redan, eden, long, road, alps, etc., were quite identifiable as to their origins.
Of course, the same could be said for the features on the courses in GB. Have you seen pics of the Road Hole bunker at St. Andrews or the Alps at Prestwick circa 1910, for instance?