Usually the business model is the company pays the credit rating agency to get their debt rated (hence the classic conflict of interest situation). Unsolicited would suggest this was not the case.
I highly doubt Dimensional are using a three factor model to manage their portfolios. Typical multi-factor models these days can have anywhere from 10 to 100 factors.
The concepts of the three factor model are important to learn but implementing one in practice is rarely done. These core factors are too crowded these days as all the quant funds are looking at the same factors.
It'll be interesting to see if we still have as many Whatsapp-type apps in future. It seems like there's already quite a few... WhatsApp... WeChat... Line... Kakaotalk...Viber...