Hi, Larzz ... I see you're in the Netherlands. You're lucky you could get
Two Mules for Sister Sara ... it's not available on Region One DVD as yet.
I think of the Eastwood Western "canon" as comprising ten films ... no more, no less.

Three by Leone:
- A Fistful of Dollars (1964)
- For a Few Dollars More (1965)
- The Good, the Bad and the Ugly (1966)
Three by "other directors":
- Hang 'em High (Ted Post, 1967)
- Two Mules for Sister Sara (Don Siegel, 1972)
- Joe Kidd (John Sturges, 1972)
And four by Eastwood himself:
- High Plains Drifter (1973)
- The Outlaw Josey Wales (1976)
- Pale Rider (1985)
- Unforgiven (1992)
I don't think of the other films you mention as Westerns.
Paint Your Wagon is a musical comedy, but since it does have Western themes and is set in the West during the Gold Rush, it might belong in a really comprehensive Western collection.
On the other hand, I can't fit
The Beguiled into the Western genre at all. It has nothing of the themes, motives or genre commonplaces of the Western except for its general chronology; it's set during the American Civil War. But so is
Gone with the Wind ... and few would consider that a Western.
KC