I disagree. I think Joel is a 9w1. He's extremely passive and self-forgetting, perpetually kind and a follower, absolutely not confrontative but with repessed anger. Often feel ignored by peoples. Clémentine in comparaison is clearly a 7w8. She's always driven to compulsively seek excitment and excess to avoid pain. She have'nt the secretive nature of the 4w5. I agree though that she is Sx/Sp, Joel is more an Sp/Sx than an Sp/So, I think.
Joel and Clémentine are clearly IxFJ and ExFP, but I can't decide about the N or the S. I'd say more INFJ for Joel and ESFP for Clémentine.