Mrs. Mann or Mrs. Corney?

One carp I had with Bleasdale's revision of OLIVER TWIST (one of many in fact) concerned his switching the name of Mrs. Corney the workhouse matron with that of Mrs. Mann, the matron of the branch-workhouse (or "baby farm") where Oliver spends most of his early years. Now this wasn't the first version to do this (they did the same in the George C. Scott version, or rather they redubbed Mrs. Corney "Mrs. Mann", and gave her original name to the Old Sally character). One wonders why? Mr. Bleasdale said his reason was because he couldn't handle silly names...then why didn't he rename Mr. Bumble or Mr. Fang the police magistrate? Personally, I think he should have stuck with Mrs. Corney's original name, after all, she was the bigger character and thanks to the musical, it is the name most people remember. That's my opinion, anyway.