The two halves are equal.
As far as "The Law" is concerned, it is of no consequence in this context.
Here we go again ... another rede thread eh ?

I dunno ... i read all through the link that EBS provided and one of the things that the author suggested was that the the main reason the rede was put out there was to provide a moral & ethical compass for the solitary practitioner.
It's a good beginning but it only goes so far. It's only one part of a much larger
integrated system of ethical concepts.
The beginner might see only the "do no harm" part but when you add the "do what thou will " part it begins to take on a completely different meaning altogether. Maybe that means do no harm while making your will manifest.
Given the historical context of 1950's England it might also mean practice your religion as you see fit ( within the framework of your tradition ). It might upset the Christian establishment but they have no moral right to make a fuss about it as long as nobody is being harmed in the process.
No harm / no foul .... right ? As long as nobody is being harmed the law of the land has no business interfering in your affairs.
So ... there are good reasons for doing no harm but it's all to lay the groundwork so that you can go out there in he world and make
YOUR WILL manifest.
Which part is more important ? Doing no harm -or- making your will manifest ?
Given that " love under will shall be the whole of the law " i think that making your true will manifest is more important than doing no harm.
After all .... we all know that it isn't always possible to do no harm while doing our thing so there's the principle of threefold return. Basically it's saying, go ahead and do the wrong thing if you must, but know full well in advance that you are fully responsible for the consequences of your choices and actions. Forget divine salvation .... everyone pays dearly for their sins in this lifetime.
Does this make any sense ?
All the different concepts fit together like a jigsaw puzzle to create a picture of an intergrated system of ( Wiccan ? )ethics.
One concept, all alone by itself, is out of context.