From my own experience I don't think it will work long term. Once the texas gets big enough to challenge the oscars it is not going to leave them alone. Texas are bullies and like to start fights even if they can't win them. Once it gets big the oscars will not be able to hang with it. Oscars are all bluff and posing, texas are not bluff, they will murder a fish that they think is weeker very quickly. Plus 2 adult oscars is going to be a ton of bioload on only a 120g.
It could work but you are going to have to do a ton of water changes and be ready to move fish very quickly when the texas gets a little bigger if it decides it doesn't like any of them.
It could work but you are going to have to do a ton of water changes and be ready to move fish very quickly when the texas gets a little bigger if it decides it doesn't like any of them.