How to delete/change strategies that are assigned to delinquent customers

Summary

How to delete/change strategies that are assigned to delinquent customers

Content

We are implementing the advanced collections in our dev instance and completed the required setups. After running the collections scoring and strategy assignment program the strategies those are assigned are seems wrong. We have disabled all seeded strategy groups and created a custom one but in the screen the seeded one is showing as disabled and in use "Yes" and customers are assigned  with this strategy but we are expecting custom strategy to be assigned for all customers. Is it possible to delete this delinquency data. Can anyone review the screen shots and advise.