The Mounted Pairs system is new to Suikoden III, and can be utilized by pairing Hugo with Fubar, Franz and Ruby, and Futch with Bright. The obvious advantages of mounted pairs is that the unit now shares the pair's total HP and attack power. What is less noticeable is that the number of swings, continuous attack, critical hit rate, and possibly accuracy, repel and other stats are taken solely from the rider. Damage received is ratioed by the amount of HP each character has to equalize their HP.
Mounted Pairs still allow the beast to make commands, but using any of the beast's runes will render the rider useless for that turn. Each beast has a command attack rune (Fubar has Shining Wind Rune, Ruby has Shining Wing Rune, and Bright has Spreading Flame Rune) that will only deal damage based on the beast's own attack power; the rider's attack power unfortunately cannot contribute to the beast's special attack. Because using the beast's rune commands does not utilize the powerful mounted duo and essential reduces the Mounted Pair into a single spell caster, I recommend giving them runes that automically aid the rider's normal or command attacks: Fury, Warrior, Double-Strike, Violence. However, the interesting thing about commanding the beast when it is a Mounted Pair is when you select to use items that are equipped to the beast...
When the beast uses any item, the rider will still opt to attack. This opens up the chance to use any items of your choice, from curative items to foods that can cause status changes and heal to magic scrolls! If you are comfortable with not selecting a target to attack, you can equip the beast with items such as Dragon Seal Incense, Boost/Fury-causing foods, Clay Guardian scroll, Soaring Bolt scroll, and Kindness Rain scroll (just like the spell, it lets you heal any pair; regular curative items can only target the pair). Your Mounted Pair will attack and use the item based on the amount of time each command takes while still using the Mounted Pair's total attack power.
Here is an example of a setup for a beast and rider to maximize abilities...
Belt of Strength
Belt of Strength
|Kobold's Course x7|
Kindness Rain x3
Soaring Bolt x1
Focus on the basics for the rider--accuracy and total damage, and overall survivability can take a secondary priority due to the shared HP advantage. For the beast, focus on adding to damage and abilities you feel you will want or need in a major battle.
* Swing is recommended to keep on the beast to increase the damage dealt from its Rune attack; it does not affect the normal mounted attack.