Gringo figures 28's are huge compared to Foundry 25's. The chunky base on Gringos doesn't help either. The 3mm difference is very apparent here, especially since the Foundry fig is on a 2mm thick MDF base. Gringo cavalry horses are even bigger. They are lovely sculpts.
(Foundry Max Perry sculpt vs Gringo Neapolitan)
I think some of the Foundry Mexicans from the old west range rather than the Maximilian range are taller though and slipping a thicker base under the lovely Foundry figures will give them a bit of a boost.