No, this scene was always there, it is just a stylistic crack.
There is certain “lightness” in the film, which contrasts with the dark and grim mood the film otherwise shows, but this short brawl scene is pretty odd.
The 3 Colizzi westerns develop a lot of patterns of the partnership of Spencer/Hill, but yes, at the same time the 3 are still different enough from the pure comedy style of theTrinity films.
Colizzi later made the first Spencer/Hill film after the 2 Trinity films ,and this one contains more adventure elements than any other Spencer/Hill comedy ,but is now definitely more a comedy than an adventure film.
Colizzi’s last film, before his prematue death, was then a Spencer/Hill comedy without Spencer/Hill (Joe e Margherito, 1974), at least that’s what I assume, cause I never was able to watch it.