The title Tarzan of the Apes (Edgar Rice Burroughs’…) from Dark Horse lists two issues:  issue #1, which apparently contains reprints from Dell/Gold Key; and Hardcover #1, which includes the first 127 Sunday-style strips from an online Tarzan comic strip (definitely not Dell/Gold Key reprints).  

Although these two Tarzan items were both published by Dark Horse, it seems a little odd that they are lumped together.  The hardcover just came out a couple of months ago, so I thought I would ask the editorial team if this is how we want to leave the title (before it sits around so long that the "it's too late to change it and mess up everybody's inventory" rule gets invoked).  

Wondering if the contents with both are collecting the exact same stories. I'm gonna guess 'No' unless you can shed some light on them. May be best to spin the later listing into its own title.

The answer is a definite no.

In 'Tarzan of the Apes (Edgar Rice Burroughs’…)' :

#1 are reprints of issues from 'Tarzan (Gold Key)'.
#1/HC are reprints of strips that were previously only available on the Edgar Rice Burroughs website (like 'Tarzan: The New Adventures (Edgar Rice Burroughs’…)' 1/HC.

The difference is that Tarzan: The New Adventures (Edgar Rice Burroughs’…) reprints are new stories that were created while 1/HC  reprints strips are based on the original books. The indicia title in the book is 'Edgar Rice Burroughs’ Tarzan of the Apes'.