One of the most important and famous battles in the Iberian Peninsula took place in Aljubarrota. There were two main parties:
Castile (with Aragonese, French and Italian support)
Portugal (with English support)
According to Wikipedia, there were over 2,000 French heavy cavalry fighting for the Castilians. Their army had a total number of around 31,000 units. Portugal on the other hand had a total of 6,500 units. Only 100 of them being English.
Portugal had a decisive victory despite being heavily outnumbered. But that raises the question:
Even though Portugal won, why did Portugal and England cheap out on troops to fight against Castile?
Surely it couldn't be because they believed that one Lusitan > 2 Spaniards and a Frenchmaid