A company has developed a chatbot to answer customer questions using a large, general-purpose pre-trained language model and the company's extensive knowledge base. During testing, they identify two major issues:

1. The model sometimes provides plausible but factually incorrect answers that are not supported by the knowledge base.
2. The model's correct answers are often too long and not structured in a way that is easy for users to understand quickly.

Given these two problems, propose a comprehensive strategy that addresses both issues. Justify why your proposed changes are more suitable than simply trying a different pre-trained model or writing a slightly better single-sentence instruction.