Taiwan has a surprisingly diverse fleet.
This is because in the eighties, they have F-104 Starfighter for High Altitude defenses and F-5 Freedom Fighter for Low Altitude. They originally planned that Mirage 2000-5 replaces the role of F-104 and IDF replaces F-5. After the successful production of IDF, the American have decided to sell F-16 to Taiwan as a replacement of IDF and IDF's production is cut from 250 to 130. F-5 is kept because of pilot transition training, which is originally done by T-38 lend from the US. When they withdraw their T-38, the role is replaced by F-5. According to '莒光園地' which is basically a Political Warfare program, the main 'selling points' of IDF, F-16 and Mirage 2000-5 are high Safety Factor, the Ability of using LGB and regular bombs and Ability of Intercepting High Altitude Enemy Planes respectively.
If you are interested in watching the program, here's the links:
Army:
http://www.youtube.com/watch?v=Cx0sR0W4Fl4
Navy:
http://www.youtube.com/watch?v=YJKp5RfLOXc
Air Force:
http://www.youtube.com/watch?v=JVZNF9mq_yU