As regards Malawi, the society over the years showed how joining any political party was a no no. Individuals have been disfellowshipped in the past for doung just that. So the Malawian witnesses new the societies view. They did not need to be told what to do.
It is like a child being taught right from wrong. The child does not need to check with the parent on every right or wrong decision they have to make in the future.
What do you think would have happened to witnesses who actually bought a membershiop card? Would they be viewed as witnesses in good standing, because their consciences allowed them to buy the card?
No they would not. Witnesses all over the world have to agree to follow the societies unique teachings and doctrines. If they do not, they can no longer call themselves JWs. The Malawi witnesses new the governing bodies view on this and they went along with it.
If the society changed their stance on this, then so would witnesses around the world. They all follow the lead of the governing body, whether they fully agree with it or not.