Probably, is your tank established? Diamond gobies usually only eat the microfauna out of the sandbed and will starve if there's not enough. Better question is do you want all the good live stuff eaten out of your sandbed and is your tank fully covered as they both jump really good.
With that large of a tank, i would say there would be enough room for them to both establish there own territories, it may not work in a smaller tank, but it should be fine in your tank.
We have our tank set up now for about 2 years. We always had aDiamond and recently bought a Pink & Blue. Shortly after, about 6 weeks the Diamond has died. I was worried that it may be a result of mixing the two! I wanted to be sure before I purchased another Diamond! Already my sandbed is getting dirty. The Diamond was awsome for keeping the tank clean!