That's a bit unfair to Pippin - it's mostly Pippin and Merry that deal with the problems in the Shire.

Davis made a lot of mistakes with him

Which is strange, because her research on the archaeological side is pretty damn good (admittedly they now think that the Romans didn't actually use the 'pig' technique of smelting, but that research postdates 'The Silver Pigs' by quite some time - and she also added a note on this in later editions). At an yrate, you're right - Petro is a great character.