Yes of course but lets not forget that Xizor and Traya are not inseparably attached to their bases of operations. Traya can leave Malachor V (*gasp*) and come for Kun directly. As in, face him on Yavin 4. How does she do this you may ask? Well of course Kun is stronger than Traya. But is Kun stronger than Traya + Sion + the Three Sith Lords of Nadd's tomb? Plus some acolytes an assassins?
The only problem with that, Xizor and Traya have fixed locations that are visable whereas G0-T0 had a stealthed yacht that could be stopped and found only by a gravtrap sensor and a gravity well generator, the former of which was expensive and the only one who could realistically afford and find one without blowing a huge sum of credits is Xizor. Now Xizor's fleet will probably be the only real threat to Kun's, given his ships would be heavily armed already without modifications done to them however on the ground? Ya...Xizor wouldn't be able to contend with all the sith and dark force users.
Traya's base of operations is really her downfall here. Given it would greatly enhance Kun and his sith allies.