such a policy we will make teachers to adhere to the same strategies that have proved to be effective for them to enhance student's performance. We will make a policy ( or implement a policy ) to have teachers adhere to the same strategies that have proven to be effective in enhancing student's performance.

I'd say this sounds better: By using a policy like this we are trying to make teachers adhere (or use stick) to the same strategies that have proved to effectively enhance students' performances.