Going to Yavin IV isn't going directly for Traya (from his point of view.) Its returning to his base of operations to plan his next move and search for Traya through the Force. I see no reasons why he wouldn't go back, being on a foreign planet, the planet of his enemy, with minimal protection is not as safe as being on his own planet surrounded by hordes and hordes of Massassi warriors.
Alternatively Traya could either start laying waste to his Massassi Warriors and Temple (orbitally) to draw him out. - he would feel their deaths. Knowing that his precious Sith artifacts (which he coveted most dearly) were being reduced to ash would force him into action. On the other hand she would lose the element of surprise and Kun would at least be expecting an attack. Another avenue Traya could take would be assaulting Malachor V itself, destroying his above fleet and then invading Malachor. But this would be difficult as Kun would be entrenched and Traya would have to face Kun personally (albeit with Sion & Sith) in a darkside nexus.
Or, Traya could wipe out his Massassi warriors and his Temple, jump to Malachor and destroy his remaining fleet, jump to Mandalore and steal a Basilisk droid, then jump back to Malachor, and have a Basilisk droid fly down to the surface and drop a proton bomb on the Academy. ()
And while I fully agree that the vessels in Kun's Mandalorian Fleet had a larger number of laser batteries, this does not mean they were more powerful. Numbers aren't everything. We also have to consider firepower, size (of the vessel), speed, maneuverability and shielding. Given the class and accomplishments of the Centurion, we can assume that it excelled in those fields.[/COLOR]