Advanced Collection - Collection Level and Collection Method Changes after Go Live

A client is using Advanced Collections - with the Collection Level set to 'Account' and Dunning Plans enabled.

Module would be more effectively used if the configuraiton were changed to Collection Level 'Site', a new scoring engine was defined, and Collection Strategies were enabled to replace Dunning Plans.

Looking for guidance on any difficulties if a production environment is re-configured in this way. Since customers are already scored, at the Account Level, and Dunning Plans have been executed, are there any potential problems that might occur?

Also am wondering if there is a need to purge Dunning History, reset delinquencies before re-scoring and running the Strategy jobs for the first time?