No, i'm saying that people who do this sort of thing won't be put off by a short prison sentence any more than they would be by a lot of community service. Will prison do anything good for these two? Unlikely. Will it put other people off doing similarly stupid things? Unlikely considering this is a very very rare case so it clearly isn't a big issue.
I don't see the point in throwing away a few hundred thousand pounds worth of tax payers money to achieve nothing. They are not dangerous. They don't need to be removed from the streets for our safety. They haven't hurt anyone. People get far less punishment than they guys will for hurting or killing someone in their car by doing things that are a danger to the general public. Work that one out...