Some of the journey guide events certainly need tweaking. After meeting the requirements the battles that comprise the character's journey should be somewhat challenging (and therefore rewarding) but first and foremost they should be fun. Some of the battles I've struggled with over the years have actually spoilt the experience for me due to their ridiculous difficulty. Others seemed too easy. I don't think they play test them properly with the characters that met the requirements (you should not need them to exceed the requirements in my opinion).
Most of the current journey for me which is GL Leia has been fine, but there was an early battle involving Rolo and Captain Han against Vader that needed me to spend a lot of time researching, watching videos and ultimately remodding them completely to beat it. Frustrating rather than fun.