I did notice something in this article. It refers to Russell as "the first leader," not "the first president." Russell was secretary-treasurer in the early days; he did the writing and publishing.
The president of the organization before it became legally incorporated was William Conley. He provided the majority of the start-up capital, but stayed with Zion's Watchtower for only a few years. Today's WTBTS does not say much about the first president; he was their first notable apostate!