Seeing that a published version of HFG is now appearing (despite the apparent problems of exactly who is publishing, and what it is), I'm putting the army lists I wrote a few years for this important war onto this forum. They are the same ones that are on the HFG Player's Handbook site. I understand that there are no lists for any South American wars included in the publication, so I hope these lists will stimulate some interest.
Suggested lists for US-Mexican war (50 – 120 AP)
1 x Inert HQ @ 10AP or Inert CP @ 5AP
0-1 x Elite Stoic foot @ 5AP
2-15 x foot, up to ½ Stoic @ 3AP, remainder Inferior Stoic @ 2AP
0-1 per 5 foot, Marksmen @ 2AP
0-1 x Heavy Cavalry @ 5AP (Cuirassiers and Lancers)
1-6 x Light Cavalry @ 5AP (Lancers, Mounted Rifles and Hussars)
0-4 x Light Horse @ 2AP (Irregulars)
0-2 x Smoothbore Artillery @ 8AP
0-1 x Strongpoint @ 10AP (Convent, presidio or similar)
0-2 x Entrenchments @ 15AP or Redoubts @ 5AP* (only with Santa Anna [Inert HQ] and defending Mexico City)
1 x CP @ 15AP or Brilliant CP @ 30AP*
0-1 x Subordinate CP @ 15AP
0-1 x Elite Bayonets @ 5AP* (Marines)
1-6 x Bayonets @ 4AP (Regulars)
0-4 x Inferior Bayonets @ 3AP (Volunteers)
1-2 x Dragoons @ 4AP (Dragoons and Volunteer mounted rifles)
0-1 x Elite Light Horse @ 3AP or Dragoons @ 4AP (Texas Rangers)
1-2 x Smoothbore Horse Artillery @ 16AP
0-1 x Smoothbore Horse Artillery @16AP or Smoothbore Heavy Artillery @ 12AP*
0-1 x Supply Base @ 8AP
Options marked * apply only to Scott's Mexico City campaign.
Explanations and Justifications
In general each element represents the lower number of troops given in the rules, so foot elements can be taken to be about 1200 – 1500 men each, and mounted about 700 – 1000. Artillery elements are about 16 – 24 guns each. Both sides had potentially large armies, however, the area to troop ratio meant that actual field battles were of a modest size.
The US took the initiative in almost every field action, so I've rated them as Aggression 4. The Mexicans did try to take the offensive, and did at Buena Vista, but fought the war very much on the back foot. They were not totally passive, so I've rated them as Aggression 2.
The Mexican war effort was handicapped from the start by the country's chronic political instability. Military success by any officer led directly to political ambition. Officers were chosen for political reliability rather than military ability. General Paredes used his army to overthrow President de Herrera in early 1846, rather than fight the Americans. He was himself overthrown in August by Santa Anna, who even obtained US President Polk's assistance to return to Mexico through the US blockade! In total there were some 8 or 9 changes of government between 1846 and 1848.
Mexican foot are described as firing rapidly, but not aiming well. During the war, several units fought to almost to the last man, and taking positions around Mexico City, such as Chapultepec, cost the Americans heavy casualties. Stoic seems the best way to classify them. Inferior troops represent the Actives militia battalions and the new armies raised by Santa Anna to face Scott's army. The Elite unit represents the Supreme Power Grenadiers or similar; ordinary Stoics are the Permanentes regular units. The Light Infantry regiments were made into Line regiments in December 1847, so in the absence of evidence to the contrary I have assumed that they were employed as ordinary line infantry on the battlefield, but possibly of a slightly higher quality. The attack and subsequent stand by light infantry at Buena Vista/ Angostura is equally well represented by Stoic elements. Such skirmishers as are mentioned in accounts are best represented by Marksman elements.
Cavalry were generally good. However, they were not well used, and tended to be deployed by regiments rather than in brigades. As such there is a very good case for regrading any or all the cavalry as Inferior. If you choose to do so, then the Heavy Cavalry element should be replaced by an element of Inferior Cuirassiers and the number of other elements doubled. I know of no incident where Mexican cavalry dismounted to fight as dragoons, so have classified the bulk of them as Light Cavalry. Again, this might be an overly generous grading; Light Horse might be a possible grading for all the cavalry except the cuirassiers, with the Irregular units being classed as Inferior. The lance seems to have been the favourite weapon of the cavalry. With the exception of the Tulancingo cuirassiers, the first company of every regiment was equipped as lancers, and other companies may have been.
The artillery tended to be scattered around the country in garrisons. Compared to the US, Mexico lacked artillery, especially mobile artillery. The horse artillery brigade had been disbanded in the 1830's because of the difficulty of maintaining it. Although the Medical Corps was reasonably well organized, logistics remained a perennial weak point in Mexican armies, with soldiers relying on wives and families for support, so no Supply Base is allowed. As well as being equipped with second hand British Brown Bess muskets and Baker rifles, Mexican armies lacked good quality gunpowder. One American commented that Mexican gunpowder was little better than powdered charcoal.
Unlike the Mexican army, the US did not fear political ambition by successful generals. The Duke of Wellington described Scott as "the greatest living soldier". Commanders trusted their subordinates and allowed them the freedom of action to make the most of their talents.
US troops were well trained and aggressive. Unusually, the majority of the army was made up of regulars. The volunteers fought well, but were inclined to be indisciplined, hence the Inferior rating.
How to class US cavalry is tricky. The regular units were dragoons, and equipped with the breech-loading Hall carbine. They were supplemented by volunteer regiments of mounted rifles. Although they performed better than their Mexican opponents, I don't think they really rate as being heavy cavalry, so have stuck with the Dragoon classification. Texas Rangers are another problem. Although they operated primarily as scouts (LH) there are reports of them dismounting to fight like dragoons so I have given a choice of Light Horse or Dragoons. The Light Horse are graded as Elite because of their high opinion of themselves, their contempt for the enemy, and their widespread use of 6-shot revolvers.
The real battle winner for the American armies was the artillery. One reason was its mobility. During the war, the US forces employed only light or horse artillery batteries, giving them a decisive advantage over their Mexican counterparts. Non-horse/ light artillery units served instead as ordinary infantry.
Although US logistics weren't that good, they were rather better than the Mexicans' so I have given a Supply Base to the US forces to reflect this. It also helps to boost the US morale.