So I have a 3 inch Oscar in a 55 gallon right now. I'm getting a 100 gal soon. I know Oscars are fast growing fish and JD's are slower growing. I wanted to add a JD to the 100gal along with my Oscar. Now I don't want the Oscar to outgrow the JD and kill it.. I don't know if this is possible as I do know these types of fish do need territory and are aggressive.. my main question is , do I buy a larger JD or one the same size as my Oscar?