Last year paulsgruff tried to do something similar, though he used more complicated approach. You can find details
Here.
The problem I see in your approach is that some of the attributes should only be considered in a combination, and some positions require certain instructions. For example, if a player with great creativity but low decision is given much creative freedom, I doubt you will get what you really want. Or if a TM has high ratings for stamina and workrate => given high closing down instruction, he might be out of position too often, etc. More importantly, it is generally possible that you have "crazy" instructions, like CDs close down often and has mentality 15, while STs pass long with mentality 5 etc.
But generally you are right, individual instructions should account for individual characteristics. The only thing is how to make sure that they don't lead team to failure

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