I wouldn't put it past the Belgian Legion, these are the same men who stood 300 against 3000+ and suffered roughly 100 casualtes (only a small margin where actually killed) and inflicted more than 300 casualties on the Republicans. They entrenched themselves in Tacambaro and fought for 5 hours waiting for reinforcements that never came. They repelled assault after assault of Republican Mexicans and on at least 3 known separate occasions they actually launched counter attacks with bayonets. Eventually the Belgians pulled back into the center of the village and barricaded themselves in the church where they continued fighting even after all of their officers had been killed or wounded. Eventually the Mexican'ts decided to say "Fuck this amigo" and lit the church on fire at which point the Belgians were forced to surrender. Once the Belgians were captured, the Mexican'ts threatened to execute them if they didn't sign a protest against Maximillian (The Austrian Emperor who was married to a Belgian woman, this is why Belgian Legion was in Mexico) but they said "Fuck that shit" and the Mexican'ts decided not to execute them considering 300 Belgians just ass pounded 3000 of their amigos and the fact that if they just execute 200ish prisoners their ass is grass. Eventually they were exchanged and Republican Mexico was all like "woohoo we're all cool and shit" and then the Belgian Legion came back to Tacambaro and kicked their asses and took the village and then the Republican Mexican'ts were all like "oh shit we suck." Eventually the war was lost but not at the hands of the Belgian Legion who consistently kicked ass, it was pretty much because the US was like "Hey France get yer dudes out of Mexico, we like the Republican Mexican'ts better because Merica and stuff so go away or we'll attack yer Mexico guys." And so France backed off for some reason and left Mexico.
The Belgian Legion was disbanded in 1866 after an impressive service record. It's commander, Colonel Alfred Van Der Smissen became an officer of the Royal Guard I believe and his experience fighting insurgents came in handy when he suppressed a workers revolt in Liege. Van Der Smissen was a bad ass motherfucker who fought in the French Foreign Legion in Algeria where he first learned how to fight insurgent losers and in 80 days he fought 26 battles and punched the rebels' poop in. In Mexico he was extremely annoyed with the French top commander, Marshal Bazaine, because he was being irrationally cautious and conservative whereas Van Der Smissen was all about the offense. At one point when word had arrived that a large Republican column was advancing south, Van Der Smissen asked Maximilian for permission to lead a division of Imperial Mexicans, French Foreign Legionnaires, and the Austro-Belgian brigade which would have been the vanguard. He vowed that a great victory would be won and that it would change the whole war and the Emperor was fascinated with the idea but nothing ever became of it. It shows Van Der Smissen's aggressive tactics and bravado though and he was one of the Empresses favorite people. He eventually committed suicide because his mental and physical health had deteriorated with old age and he couldn't stand to not be capable of doing his job so he ate a bullet for breakfast.
