No account I've read, including Rickards', identifies exactly which purported guerilla band participated or how many men they had.
You may want to reread - From Rickards: “ … a group of two hundred and fifty men brought from Cotaxaba and Cueva-Pentada by Hilario Osario to join Milan’s forces. 5 - 5 Lande/Maine, ‘Cameron’, 451-52
“Here were many of them, each able to call upon his own adherents and followers: Pascual Rincon of Timexcal, who was probably already at Milan’s camp, Matias Gonzalez of Cueva Pintada, Honorato Dominguez of San Diego, Marcelino Rosado of Pase Del Macho, Zeferino Daquin of Cocuapa, Tomas Algazanas of Coxtaxla, Inagacio Gonzalez of San Jaronimo and Juan Arevalo of Coscomatepec, among others.” 27 – 27Penette/Castaingt
Even your account states that all the Mexican infantry came from the national guard battalions. The French report more Mexicans than the Mexicans do but there's nothing to back it up.
The few repatriated enlisted men were hardly in a position to accurately count the number of soldiers on the other side shooting at them -- it doesn't surprise me that they thought they were outnumbered 30 to one rather than 14 to one. “It's a mistake any of us might make.”
Except they were veteran soldiers on the scene and we’re not.
Milan's after action report includes the statement that "From noon the battle lasted till near dusk, sustained by our opponents with a valor founded on the belief that we were guerrillas and would not spare their lives." This indicates that the only guerillas present were those in the imagination of the Legionnaires
No, it indicates Milan thought the French thought there were be no quarter because of the treatment of prisoners by local guerillas.
The count of 20 unwounded men comes, as I said, from one of the surviving Legionnaires.
Here’s Berg’s list of the “unwounded”:
Palman, Sergeant – bruised. Shaffner – wounded by debris in the face. Berg, Corporal – bruised head. Magin, Corporal – slight hand wound. Maine, Corporal – Segers, Fusilier – Billod, idem – Gautner, idem – Schrublich bruised side, Verjus – Seffrin, a slight bayonet wound in the chest. Holler – Vandenbruck – Schiffer – Jeannin – Merlet, hit in the head by a stone – Brunswick – Conrad, Mr. Danjou’s orderly, from the 5th of the 1st – Gorzki, a wound from a blow from a gun butt in the face – Zey - Kunassek
The French accounts of mass graves came later and are clearly apocryphal -- Jeanningros said he didn't have time to collect or bury his own casualties. I seem to recall that his account says nothing about graves or counting corpses.
From Rickards: “ Outside the back wall the Legionnaires found the trench where fifty Mexican bodies had been placed, and another nearby, in which were the naked bodies of the dead of the 3rd of the 1st. 13 - 13 Jeanningros to Forey, 4 May 1863
I think the use of statistical analyses of civil war casualties has a great deal of relevance here since the fighting was done with the same sort of weapons.
What about range, duration, experience, etc?
Rorke's Drift is relevant because it shows that even with significantly better weapons (like the breech-loading Martini Henry) against significantly more poorly armed opponents (Zulus with assegais) trained European soldiers proved unable to attain anything like the success the French claimed for the legionnaires.
Next let’s compare D-Day to the OK Corral, it should be relevant
Sergeant may have found the losses inflicted believable, but he obviously didn't crunch the numbers
My “Internet guy” reference was found offensive but this is it in a nutshell. Ignoring the author’s combat experience he still wrote a book with dozens of sources and spent a year or two or three of life doing so. I’m loathe to toss out his writing based on your opinion just because you say so.
I’ve about reached the limit of effort I want to spend on rebuttals. Once again - anyone interested should read what’s available and not rely on the interpretation of others (myself included). You never know when someone might have a predetermined agenda and be willing to skew a few facts.