The missiles and laser repeaters on the Nova are realistically the best defense against ships attacking it, as the main cannon does not have the speed or articulation to hit fast moving targets. When considering damage output, those weapons might be enough to deter a dedicated fighter like the ones mentioned but not for long. Using modern day scenarios as an example, the best use of tanks is with combined forces against an unprepared enemy or lower tier fighter it should be able to hold its own easily.