I don't know Red Dead Redemption of any variety or number because I am really old, but it is easy to imagine what your example looks like because the primary source record is so full of these images - that's assuming that we can accept Hollywood movies as primary sources. Here, for example, is an excellent depiction of an extended bar brawl scene from Mel Brook's Blazing Saddles (1974 - you may want to jump to around 1:10). Is this accurate? It is for Hollywood, but not so much for the West.

That said, here is an image from J. Ross Browne (1821-1875) who visited Virginia City, Nevada in 1860 when it was barely a year old. Browne was a travel writer and illustrator for Harper's Weekly. Browne's work was often tongue-in-cheek and here he is feeding the Eastern appetite for Western cliches. This illustration is titled "Home for the Boys," shows a saloon called the "Cosy Home" offering "comforts" for its clientele. This was exactly what people thought was going on in Western saloons in the 1860s, just as it fit the stereotype that Hollywood capitalized on - and Mel Brooks exploited.

So, then the question is whether this is realistic for the period - as you are asking. In all my four decades of pouring over primary source records that were not a matter of satire as in the work of Browne, I have not found this sort of fight. There were, of course fights: young men with alcohol in a small space will result in some flaring tempers and physical contests, but the pattern that is repeated throughout the records are two men fighting with or without weapons and with their friends trying to deescalate the conflict or attempting to pull a wounded comrade away from an assailant. Large bar brawls make for good drama, but they were not the norm from everything I have read.

At the same time, your Red Dead Redemption 2 is certainly following a time-honored tradition of depicting the Wild West as a place of violence, often with large groups of men fighting one another. It is part of the image of the West, and to paraphrase Samuel Clemens (who took his name "Mark Twain" in Virginia City in 1863), "a lie will travel around the world before the truth gets its boots on." Sometimes we can learn a lot from a lie, since it speaks to what we want to believe as opposed to what is true.