The Thais and Laotians are distinctly different cultures with different languages. Don’t argue with me, ask my Laotian wife and Thai ex-girlfriends.
As far as Thais needing tanks to use against Laotians, that’s nonsense. Use against the Muslims in the south or on the Burmese border is what this is about.
The Laotians are still in a semi-civil war. Thais and Laotians otherwise get along fine.