There's a reason for the similarities. JMS pitched B5 to Paramount with a series bible that included: A numbered space station (Babylon 5), ships coming and going via a "vortex" near the station (the jumpgate), a race recently emerging from occupation by another race (Narns from Centauri), mysterious unknowable aliens (Vorlons), and a shapeshifter (the Minbari with the changeling net).
Paramount said no, and then greenlit a new Star Trek series with: a numbered space station (Deep Space 9), ships coming and going via a vortex near the station (the wormhole), a race recently emerging from occupation by another race (the Bajorans from the Cardassians), mysterious unknowable aliens (the wormhole aliens), and a shapeshifter (Odo).
While JMS doesn't accuse Berman and Piller of having ripped off his concepts, he does suspect that someone in Paramount might have mined his treatment for ideas that they then pitched to Berman and Piller. Nonetheless, both shows went different directions and produced some high quality tv sci fi.