I think something that should figure into the equation is that Wlad is out of options, so if he doesn't make the team, the Reds will most likely lose him.
Now WLad may turn out to be Ruben Mateo, or he could turn into a valuable player. He showed sign in his few weeks with the Reds that he could be a valuable player in the long run.
So the question is, "Does the additional production that Gomes would provide in the short term outweigh the possible future production that Wlad may provide in the long term?"
It's a tough question without a clear cut answer, but my answer would be no. I would rather stick with Wlad and take my chances. His upside is worth the risk, especially considering that Gomes' ceiling really isn't that high.