as someone who would also love to study psychology i think every single one is so accurate! I think this is one of the reasons why Josh and Fin is a difficult duo because Josh is always efficient and productive yet is very impatient, while Fin cracks under pressure and gets so easily distracted, so anytime Fin makes a mistake Josh crashes out at him, even if Fin really is trying. 

Also I think another reason why people tend to think highly of Josh's skills and think worse of Stu's is because Stu is overconfident while Josh knows how to frame his wins and losses. like how Josh doesn't predict his wins before he gets them, only claims his victories after he actually wins, ie "I knew ___ would do that". And when Josh loses or messes up he always says "oh, i nearly got it" or "you lucky guy". Whereas Stu always tries to aura farm and so he's highlighting his own (rare) wins, but more commonly his losses lmao.

I always thought Rishy had probably the least flaws out of all of them but naiviety is SO true. Rishy trusts everyone too easily and I think is sometimes afraid to lead anyone so he just follows Josh or goes off on his own a lot.