According to Magwitch, why did Compeyson get a lesser sentence than Magwitch when they both got into trouble in Great Expectations?
This is the typical problem with our court systems. Magwitch's basic assertion here is that the judges are discriminatory or that they apply sentences unjustly. Aren't the courts supposed to be just? Aren't the courts supposed to be the one place in a society in which all people are treated equally.
Magwitch would also assert that his involvement in their crimes was to a lesser extent than that of Compeyson.
Compeyson was having a pity on nothing and nobody.
So I begun wi' Compeyson, and a poor tool I was in his hands.
Magwitch here notes that Compeyson doesn't care about anyone but himself and is willing to sell out a friend or partner. Magwitch calling himself a "poor tool" demonstrates his understanding of his place with Compeyson.
Compeyson also insisted that they didn't communicate during their trials and that they received separate defenses.
You can find the answer to this in Chapter 42.
Compeyson and Magwitch had been accomplices in crime. When they were caught and put on trial, though, Compeyson arranged to have a separate lawyer and a separate defense.
The reason for this is that he was going to blame all the crimes on Magwitch. So Compeyson gets a lighter sentence because he blames it all on Magwitch. His lawyer points out that Compeyson is younger and from a better family than Magwitch. He says this shows that Magwitch is the one who is really at fault and Compeyson just got in with the wrong crowd and shouldn't be punished as harshly.