I think it's less an issue of encounter balance and more that Pathfinder is difficult at lower levels by design, which wouldn't be so bad if it wasn't for the poorly built companions (the main issue). The companion you rely most on to hit things in the early game is Amiri, the 16 Strength Barbarian who specializes in a weapon that reduces her attack rolls by 2... Your main support is Harrim, the 10 Cha melee cleric with 8 Dex, and Linzi, the bard with 14 Con and 8 Str that hits medium load while carrying a crossbow. If you're feeling adventurous you can go with Jaethal, the undead that burns through all of her spells/day for self-healing. Then you have Valerie... the Fighter with FOUR uneven stats, her highest being 19 Con(!) and 15 Cha(?), who sacrifices everything in order to have good AC (poor reflex/will, poor touch AC, poor attack rolls, poor damage, no skills, no utility).