With a passing siding at top of outside loop, you could easily have two trains running on that loop unless you just want to sit back and watch three trains chase their tales.
Hint: Consider the potential boredom factor when designing a plan. Right now, your outside loop can only handle one train and your inside loop can handle two trains, but only running in the same direction. You don't even have enough room to take one of the inside trains to the outside loop to change directions unless your inside loop can temporarily manage all three trains running in the same direction.
Your plan leaves no space for operating accessories, for excess train storage, or for any operations (e.g. switching cars for industries, refueling, passenger stops, etc.). In the planning stage, consider what you need to be happy and then be sure to incorporate those needs in your plan.
Chuck