Calculating scores and issues creating quiz

Hi there, 

I need to create 2 quizzes on Storyline. Each quiz must alternate 2 assessment papers. 

The difficulty I'm having is with the scoring. The assessment papers have a mixture of question types and I need to be able to assign 2 marks for 2 correct answers, or 1 mark per correct answer. But on the graded questions, a lot of them don't allow me to select scoring "by choice" and only give the option to set the score "by question" - which seems unintuitive to me for the multiple response graded question. 

It has led me to try and use variables to set specific triggers to amend the scores and I am going round in circles. I am unable to get my head around best practice to do this. 

Can anyone advise please?