Johann,
If helper "of many, and of myself also" does not mean that Phoebe was a ruler over Paul, then it doesn't mean that Phoebe was a ruler over "many" either, and if it doesn't mean that, then the word translated "helper" doesn't mean "ruler" or "leader." And if the word doesn't mean that, then the article is wrong, period.
Of course, if I ignore the wording of Rom. 16:2, then I might just buy into the fallacious reasoning of the article. But we're supposed to stick with Scripture, aren't we?