All five character classes use four basic stats: attack, agility, intelligence and health. Training your troops (and leveling them up) will increase these stats. Here is a quick brief on all four stats in order for you to determine which training regimen is best suited for a particular class.
Attack – determines how much physical damage a party member will deal. The only exceptions to this rule are mages and clerics, as mages use magic to do damage and clerics rarely attack at all (but when they do run out of MP and start attacking in melee, it is believed that this stat is the determinant factor).
Agility – controls a unit’s movement speed and also increases a character’s defensive trait (this makes “swordsmanship” training the best choice for a tank). Movement speed is a critical factor for melee characters as this determines how fast they can charge forward, and how well they can recover after being pushed back. Against a hail of arrows, a knight will need plenty of agility to break through.
Intelligence – governs only one aspect: magical capabilities. This makes this trait useful only for mages and clerics. As this trait is what increases their abilities, selecting chess training for the two classes is pretty much a given –though an occasional try at stamina or swordsmanship training would not hurt either. The only way to increase intelligence outside of leveling up is through chess and reading.
Health – determines how much HP a specific character has. Simply put, the more HP you have, the more likely you are to survive a battle. Naturally, those on the forefront –soldiers and knights, are the ones that benefit the most from having this stat increased.