I understand that. While I would hope they would redesign the plane to decrease the drag further, it is more likely that the design will stay as it is and incremental engine improvements will be the most likely way to increase the Thrust/Drag.
While we purchase from amongst engines that are available, If in the future, PAF switches from the RD-93 to a Chinese engine, it should insist (have a requirement) the engine have enough thrust to exceed the Thrust/Drag of the Mirage 2000. Similar to the development of the GE 414 Engine. Currently at 22,000lb at max thrust but the EPE is at nearly 24,000lb max thrust and future growth is projected at up to 26-28,000 lb max thrust.
http://pds24.egloos.com/pds/201112/12/24/f0082824_4ee4d2f80971f.jpg