With all due respect, but you can not compare Knopfler with Clapton. They both play guitar and sing, but that is where the resemblance stops.
Clapton is not a songwriter and creative artist. All the hit songs he put out there are covers or songs he had in one or the other way help with, to make the song from bad/mediocre to good/great. Because Clapton is not creative he comes up with things like a total uninspiring Christmas album filled with Christmas songs, which probably are all covers.
To be honest, I don't really understand why Clapton operates the way he does. He has all the freedom/time in the world, because of all the wealth he gathered. If you aren't a great songwriter then write down some lyrics in which you say what you want to say about the things that touch you and are important to you. After that get help from someone who is a great writer to help you rewrite those lyrics to make them better. When the lyrics are finished then go experiment in the recording home studio and try to put some chords/music underneath it. After that call up a good producer and get the band together for recording sessions.
Now it's like he has no dept and hasn't anything to say to the world.