Earl Clark seems to be making the mistake of thinking short term. He might get a 2 year deal or whatever but he will be playing behind tristan thompson for sure. And Mike Brown isn't going to play earl clark, he is going to have his ass at the end of the bench. He won't even be able to show out anything he's learned or improved upon.
With the lakers he will be a starter guaranteeing him more playing time for a bigger payday down the line when the lakers have other contracts off the book. If he goes to cleveland he will go right back into obscurity and people will forget about him again.
He needs to do what he needs to do.