True. But those assassins weren't taking over a ship that was under Revan's control.
I'd like to point out that since Revan would've been using those aggresive tactics, Traya wouldn't have been able to use his morals to defeat him. She feels that if one was to go to great means to sacrifice something for others, then that person is weak. Revan is not weak in this since. If one of Revan's ships was begining to be overrun, he'd probably shoot it down, regardless of how many survivers were on board.
One more thing: In Traya's opinion, looking at Revan is like "looking into the heart of the force." She believes he's very powerful and a great general. Just saying....
Question: Does Revan get his generals? Like Malak, Meetra, and Karath?
If Revan did destroy his own ship, he just cost himself a vessel. This is inconsequential to Traya as that is the plan. Her assassins would cause confusion. Revan attacking his own ship would cost him more than it would Traya.
And as to leadership. The Sith who joined Traya recognized her as Revan's master and joined her without question. They were fiercely loyal and would not betray her unless they got some one on one time with Revan.
If Revan gets his generals, then Traya gets her greatest students. Just sayin.