Medieval armies can be dated from the style of armour and clothing that they wear.
The Fireforge Mounted Templar Knights are equipped with armour that is from about 1180 - 1250.
The Perry Agincourt Range are dressed for 1415 to about 1435. Mounted Knights are planned but you may well have to wait a year or two.
The Perry WOTR Range and European armies are dressed for 1455 to 1485. This range includes mounted men at arms and also mounted light cavalry.
Even though they are later than the Perry Agincourt range, they could be used as a substitute until the Perry Agincourt mounted sets are produced.
I did us some Firforge Templar horse bodies with Perry WOTR mounted figures to give me mounted Swiss generals.