Lochar-Tamang too
There's no black and white distinction on these matters. Things get blurry as people migrate and assimilate with the new environment. The proper name for all of them is "Tibeto-Burmese" according to Western term and all of them fall under that category to make things easier.
As far as I know, Manang are almost like Tibetan and Sherpa in term of culture and religion, except for the language which is more Tamang, if I'm not wrong.
"Subba"? that could be mean a type of government post too, so there's no surprise there.