I really love making Int/Charisma based characters, 15 Strength, 15 Agility, then 30 into Charisma the rest into Int, that allows me to put 10 in Surgery, Wound Treatment, First Aid, Training, 5 in Riding, and Horse Archery, 5 in Power Strike, Iron Flesh, and Archery, which is enough to be able to pass your book quest.

The reason for this is because unlike your allies, you gain a bonus to your skills based on how high they are, and for the rest of your allies you can just pour them into Strength with 15 Agility for 5 Riding Skill, and Shield, or Archery, and Horse Archery, etc.

If your ally has 10 Surgery vs your Surgery, you have 14. Which does count towards allied deaths, meaning that instead of losing 30% of your units per battle, you'll lose like 15 - 20%

Of course at the later levels when you've maxed Inventory Management, and gotten Prisoner Management to like 6, you can begin pouring whatever levels you get then into strength to beef yourself up.