The sofas are actually just about the perfect size - just because you have a wide-open room doesnt mean you need to jam in the longest sofas that will fit.

You need breathing & circulation space between the sofas and the hearth, and it needs room at the other end to allow for the bench to not be pushed into the walkway.

On the other hand, the rug could be larger - it would be much more pleasing if the sofas and bench were anchored on the rug.