The thing that interests me the most about this movie is the year it was made: 1968. From the way I reckon things there are four or five specific periods of evolution that Spaghetti Westerns went through. A "Pre-History" period of roughly 1962 to 1964, and "Experimental" era from 1964 to 1965, the "Classic Era" 1966 - 1969 period, a "Revisionist" era from 1970 until maybe 1973, and then a 1974 - 1977 "Parodic" phase where the genre started to consume itself and fell into decline. There is of course overlap between each of those segments (i.e. Corbucci's first DJANGO film has an experimental era nature to it but technically falls withing the classic period) and there was also the resurgence era in the mid/late 1980s with films like SCALPS and DJANGO RIDES AGAIN.
But 1968 is an odd year, there seems to have been a push/pull effect going on with most of the films from that year which I have been fortunate to see, with Leone's ONCE UPON A TIME IN THE WEST being the defining moment from which the genre received a huge burst of confidence by having the Italian/Spanish industry produce a film that was on the same epic scale of stuff like THE SEARCHERS, but without the iconoclasm of THE GOOD, THE BAD, AND THE UGLY.
There was a resurgence of Experimental approaches that seems to have started after two films in specific from 1966 and 1967, DEATH RIDES A HORSE and THE BIG GUNDOWN (some might also cite DAY OF ANGER as another), which are almost "pure" examples of the Spaghetti genre in the sense that they are nearly devoid of any over references to American Western genre filmmaking and have their own unique vocabulary that is generally unconcerned with making a traditional cowboy movie. The films have a flavor and look that becomes an idiom unto itself, and in my opinion the result was a conscious attempt by some of the filmmakers to try and delve deeper into this vocabulary of filmmaking and create forms that were as unconcerned with traditional Western conventions as Leone was with appropriating those conventions and turning them on their side.
The result was movies like THE MAGNIFICENT TEXAN which seem to have their own flavor: They are readily identified as Spaghetti (and in this case feed off DEATH RIDES A HORSE) but have what I can only describe as a dynamic tension that harkens back to the experimental era where oddball combinations are paired to create a juxtaposition between the "serious" look of a Western and something more resembling a cartoon or graphic novel -- DJANGO functions in a similar manner. Another good example of this oddball dynamic is Jose Luis Merino's REQUIEM FOR GRINGO, which is a bizarre movie regardless of genre and seems completely unconcerned with the "reality" of the Western as a genre, and instead uses those conventions (gunfights, horses, whiskey, cowboys) to create a unique form. BEYOND THE LAW would be another example in that it seems to take a step backward from the stylistic excesses seen in stuff like DEATH RIDES A HORSE and the Leone "Dollar" films and instead almost tries to be a traditional cowboy movie -- which is what I am seeing in THE MAGNIFICENT TEXAN, even so far as to include a Lone Ranger type hero wearing a mask & living a dual identity. But at the same time the visual vocabulary being used is 100% Spaghetti right down to the good old sand pit scenes and overt violence (in one scene a woman gets a rifle butt smashed into her face) that would never be acceptable in a Hollywood style production.
So 1968, an interesting year for Spaghetti in that it seemed to spawn two different approaches: An epic approach ala ONCE UPON A TIME IN THE WEST and TEPAPA, and then a more cartoon like approach best exemplified by the "Sartana" series with Gianni Garko, which also got it's start in 1968. By 1969 these two formulae had branched off into separate methods of approaching the idea of making a Spaghetti Western, but in 1968 they seemed to see a combination within individual films, and the result is a very unique "feel" to movies like THE MAGNIFICENT WESTERN, which may not have contributed much that was new to the idiom so much as continuing those skeins that came before.