To supplement what Alta said, (to use SUCK, as Skalligram, if you do read this, you really went to town on Asia, sick job there mate), here's what I'd suggest for Indochina and Indonesia (It seems Skall also had a few more in other Asian parts, if you feel you would want to touch up prior areas Boris
).
Indochina
-Thailand
-Kingdom of Dvaravati
-Kingdom of Ngoenyang/Hiran
-Lavo
-Hariphunchai/Haribhunjaya
-Lanna Kingdom/Lannathai (along with your Lan Na)
-Rattanatingsa
-Laos
-Phuan (if it is distinct from Muang Phuan
-Monarchist Laos
-Tai people
-Cambodia
-Agreed some of these could be split up,
-maybe also PR of Kampuchea
-Vietnam (can't do the accents, sorry)
-Van Lang/Xich Quy/Lac Viet people
-Au Lac/Au Viet people
-Nam Viet/Nanyue
-Linh Nam (Trung Sisters rebellion)
-Sa Huynh Culture (goes with Champa)
-Malaysia
-Langkasuka
-Tambralinga
-Indonesia
-Sumatra
-Melayu Kingdom
-Banten Sultanate (can go with Sunda, or as a secondary state for the region, as there is a 50 year overlap of existence)
-Java
-Shailendra
-Kahuripan (is this Kanjurupan on the scheme? they were two split Kingdoms)
-Singhasari (Hindu Indonesia)
-Cirebon Sultanate
-Kalinyamat Sultanate
-Surakarta Sultanate
-Yogyakarta Sultanate
-Larantuka (Flores Islands)
-Sasak Principality (Lombok, perhaps can (even if not historical) United Lesser Sunda Islands?)
-Sultanate of Sarawak- White Rajahs
-Kongsi republics (Borneo- Lanfang, Heshun and Santiaogou)
-Malaku Isles (Spice Islands/Tropical Resource territory or something like that)
-Oecusse (secondary Timor L'este, given the fact it is a significant exclave)
For Indonesia as whole, perhaps add as a secondary Federation of Indonesia/ United States of Indonesia. Also a secondary for this, for East Indonesia (1946-50)