Expert retainers are trained in useful skills that are in demand among adventuring parties.  They come equipped with light armor and 1-2 simple weapons, plus appropriate items of their trade (as a GM judges).
Weak Mod:  CON, CHA, morale, resistance
Normal Mod: STR, WIS, missile and melee attacks, perception
Strong Mod: DEX, INT, stealth, three skills chosen by GM
Possible Expertises Include:
 Alchemist (Alchemy, Lore (Astrology), Arcana)
 
 Armorer: (Craft (Armorer), Craft (Swordsmith), Appraisal)
 
 Barber / Surgeon (Occupation (Barber), Lore(Animals), Medicine)
 
 Burglar (Lockpicking, Traps, Investigation)
 
 Gambler (Gambling, Deception, Insight)
 
 Guide (Survival, Lore (Geography), Riding)
 
 Herbalist (Herbalism, Brewing, Lore (Plants))
 
 Minstrel (Perform (two types), Lore (History))
 
 Physician (Medicine, Herbalism, Lore (Spirits))
 
 Poisoner (Poisoner, Deception, Disguise)
 
 Sage/Historian (Three Different Lore Skills)
 
 Teamster (Occupation (Teamster), Riding, Lore (Animals))
 
 Tracker (Survival, Lore (Animals), Herbalism)
 
 Woodsman (Traps, Survival, Lore (Animals)) 
 
Class E Expert  (Apprentice):
 AC: 12 (light armor)  HD 1/2  HP 2 
 
 Resistance: 8; 
 
 Mods: W -2/N+2/S+2
 
 Speed: 30';  Load 12
 
 Morale: -2
 
 Stealth +2, Perception +2
 
 Attack, Melee:  +2;   Damage: by weapon
 
 Attack, Ranged: +2; Damage: by weapon 
 
 Expertise:  3 related professional skills at +2
 
S +2, D+2, C -2, I+2,W+2,Ch-2
Class D Expert:
 AC: 12 (light armor)  HD 1  HP 5  
 
 Resistance: 8; 
 
 Mods: W -2/N+2/S+3
 
 Speed: 30';  Load 12
 
 Morale: -2
 
 Stealth +3, Perception +2
 
 Attack, Melee:  +2;   Damage: by weapon
 
 Attack, Ranged: +2; Damage: by weapon 
 
 Expertise:  3 related professional skills at +3
 
S +2, D+3, C -2, I+3,W+2,Ch-2
Class C Expert:
 AC: 12 (light armor)  HD 2  HP 9  
 
 Resistance: 9; 
 
 Mods: W -1/N+3/S+4
 
 Speed: 30';  Load 13
 
 Morale: -1
 
 Stealth +4, Perception +3
 
 Attack, Melee:  +3;   Damage: by weapon
 
 Attack, Ranged: +3; Damage: by weapon 
 
 Expertise:  3 related professional skills at +4
 
S +3, D+4, C -1, I+4,W+3,Ch-1
Class B Expert:
 AC: 12 (light armor)  HD 3  HP 13   
 
 Resistance: 9; 
 
 Mods: W -1/N+3/S+5
 
 Speed: 30';  Load 13
 
 Morale: -1
 
 Stealth +5, Perception +3
 
 Attack, Melee:  +3;   Damage: by weapon
 
 Attack, Ranged: +3; Damage: by weapon 
 
 Expertise:  3 related professional skills at +5
 
S +3, D+5, C -1, I+5,W+3,Ch-1
Class A Expert:
 AC: 12 (light armor)  HD 4  HP 17   
 
 Resistance: 10; 
 
 Mods: W 0/N+4/S+6
 
 Speed: 30';  Load 14
 
 Morale: +0
 
 Stealth +6, Perception +4
 
 Attack, Melee:  +4;   Damage: by weapon
 
 Attack, Ranged: +4; Damage: by weapon 
 
 Expertise:  3 related professional skills at +6
 
S +4, D+6, C 0, I+6,W+4,Ch+0
Master (Elite Expert)
 AC: 12 (light armor)  HD 5  HP 21  
 
 Resistance: 10; 
 
 Mods: W 0/N+4/S+7
 
 Speed: 30';  Load 14
 
 Morale: +0
 
 Stealth +7, Perception +4
 
 Attack, Melee:  +4;   Damage: by weapon
 
 Attack, Ranged: +4; Damage: by weapon 
 
 Expertise:  3 related professional skills at +7
 
S +4, D+7, C 0, I+7,W+4,Ch+0