http://www.uoherald.com/guide/guide.php?guideId=154
Honorable combat is defined as:
* Allowing your opponent to damage you first.
* Engaging in one-on-one combat.
* Not using ranged weapons, unless you stay in the same spot where you honored your opponent, or you only damage your opponent while adjacent to them.
* Not allowing your pets or summoned creatures to help you during the battle.
* Avoiding the use of poison.
The amount of Honor you gain from defeating your opponent is determined by how closely you followed the above guidelines for honorable combat, as well as your opponent's level of fame.
So it's harder for tamers or summoners to gain honor compared to a warrior.
For direct damage characters, it's harder for archers and mages to gain honor compared to a melee warrior.
A tactic I use on my mage to max honor gains is to let my EVs whittle away the mob's HP, then precast ebolt and run adjacent to the mob to release the kill shot.
As to the OP's concern regarding damage increase from perfection, it is not affected by your pets' (or other mobs'/players') damage to your target.