I don’t see much disagreement.
The Harvard study recommends 5 to 10 percent of energy consumption of LA. Not the 15 to 20 percent that is being consumed today according to the Mercola article.
Consistent with the American Heart Association guidelines, our data continue to support consumption of 5-10% energy
The Mercola article focuses on excessive LA consumption. It does not say a normal amount is bad, but excessive amounts are. The Harvard study doesn’t get into excessive amounts at all
Over the last 150 years, the LA in the human diet has increased from about 2 to 3 grams a day to 30 or 40 grams. LA used to make up 1% to 3% of the energy in the human diet and now it makes up 15% to 20%