Dai people got pushed south during Shu Han period. Those that stayed got largely-Sinicized. So naturally they will be interested in this part of Chinese history- not to mention a large part of the Thai people are ethnically pure or part Han Chinese due to later Minyue migrations from coastal Guangdong and Fujian(themselves havign a past history involving Sunwu period).
* atually i prefer the role of Zhugeliang- he's a brilliant strategist. He's the reason why the 'weakest' of the 3 entities, 'Shu' could hold its own agaisnt the other 2 despite being smaller in territorial size , population(a huge part of its army were drafted from Chengdu plains) and landlocked- could hold its own against the other 2.