They paid a total of 2 people...

That's not quite what TFA says. Rather:

"The UCSF researchers analyzed more than 340 documents, totaling 1,582 pages of text, between the sugar industry and two individuals...."

That is, this research (into industry influence) focused on the available and reviewed correspondence between the industry group and two specific researchers. There's nothing about this article or the referenced analysis which precludes additional other researchers being similarly influenced.