I wouldn't. And didn't. Everyone is different.
I found that I was having to refer back too much when changing subjects so I did one at a time starting with HPL, then Air Law, Met, Nav (I have to confess I never even opened the Comms books!!) etc. After going through each subject, I would start on the question bank and that was what kept me up to speed with the sbjects.
Do whatever suits your learning best.
Cheers
Whirls