That article looked pretty thin on research and evidence to me: it seemed mainly to be based on the similarity between the words 'Gollum' and 'golem', which only look alike when written.
Tolkien was once obliged to correct a Mr. Rang, who wrote to him with a number of amateurish philological observations about names in
LR, most of which had a similar basis. One of those was a suggestion that Moria was in some way related to the biblical Land of Morīah, Tolkien's comments on which may be found in
an old thread about the subject. Tolkien's main point was that a mere similarity of appearance, or even sound, was not a sign that a name was intended to have a meaning in a real-world language.
In the case of Gollum and golem, though, we are faced with the additional inaccuracy that the name 'Gollum' dates back to the composition of
The Hobbit in the mid 1930s, whereas the conception that the character had been corrupted by the One Ring did not arise until Tolkien was working on
LR. The relationship that this article assumes between the names relies on a connection that Tolkien cannot possibly have made.
Sméagol, on the other hand, is derived from Old English
smeáh,
smeóh, which has two meanings that both apply to Gollum/Sméagol: 'creeping in, penetrating' and 'subtle, crafty'. Since this name was chosen during the writing of
LR, it is much more likely that Tolkien chose the name based on those meanings.
From the above example we can see something of how Tolkien used words from real languages. Normally in his works names fit their owners very closely, without ambiguity or loose ends. Mere similarity of sound doesn't mean that Tolkien meant there to be a connection, so we should be very careful with situations where one seems to have been made.