How much has actually been left out so far?

So I know that some pretty important details are left out in the anime compared to the novel. For example reinhard being able to draw ried against subaru on their first meeting, but how many other things like this arent made clear in the anime to the current last episode (s4 ep11). Are there any other major details? I dont want any info about upcoming episodes, just what is missing in the current anime adaptation.