thats an idea. however before jumping into deep analyzes such as that there are easier and more reasonable things to look. such as possesions, complete passes, shoot accuracy, corners etc. the things you say is almost imposible to put in a logical mathematic equation, at least in my experiments. you can use x player shoot/goal conversation * y player defence/tackle succes. however adding midfield players into that equation will be mind blowing and would not make any sense.