I like historical novels a lot, as well, and I've read a lot of those you mention but I find it pretty hard to group them all together into a single genre. Clavell's books were more like rip-roaring westerns. Follett's historical novels were more like family sagas. Rutherfords were more Michener-like novellas strung together. They differ more than they're alike. They really aren't at all the same kinds of books except that they took place a long time ago. They even vary a lot in how historical they are.
I haven't read "War and Peace" so I don't know how that fits but I've always felt that historical novels were more of a broad general category than a genre.
Compare those with the books of Lloyd C. Douglass and Frank Yerby and Mika Waltari and the category gets a lot broader. I'm not really sure "historical novel" is a term that means a whole lot, although I do use the term fairly often.
In a sense, every novel is either a historical novel or will eventually become one.
Barry