but what if you're just one of those "paper work" lawyers, do you still need good communication skills?
I'm not quite sure what you consider a 'paper work' lawyer to be, but if by that you mean a practitioner who does not do advocacy work (i.e. court work), you absolutely need good communication skills.
You need to be able to provide written advice and analysis that is concise, correct, intelligible and generally well written. You also need to have a good grasp of research skills, which is linked somewhat with English language skill.
I wouldn't say that obtaining a certain mark in a certain English course is a pre-requisite, but if you were not doing Advanced English and you were not receiving top 2 band marks in whatever subject you are doing, you may struggle a little at first.
Plenty of people I know did poorly in English in the HSC and are now doing fine in a law degree, however, they also put in a lot of work and study to improve after not doing so great in first semester.