My overall understanding about TPACK and PCK is about finding the balance.

Whether it’s finding the balance point between Content Knowledge and Pedagogical Knowledge, or PCK with Technological Knowledge. PCK refers to the finding the best method to teach the content in a way that enhances students’ learning and integrating technology into this creates TPACK.  Like many others also pointed out when using TPACK, innovative teaching methods, keeping current is very important. Using technology effectively in the classroom by knowing which technologies to use for what content can support learning.

I came across this video that explains these models very well. https://www.youtube.com/watch?v=yMQiHJsePOM