Just a little bit of a correction, tulpas only sometimes fall into the category of headmates. It really depends on the tulpa. A lot of tulpamancers project their tulpas into imaginary friend like things that they can visualize following them and such. Also, quite a lot of tulpas are unable to actually switch (switch places with the host). Some can do what is called possession which is sort of an in between where the tulpa moves one part of the body such as the hands. (1/2)

But for the most part, from my own experiences along with what I have gathered from others, the majority of tulpas seem to exist in the projected state which is very different from a headmate. There are still some that could be considered headmates, but for the most part they are separate things. I would however, consider them to be fictives if they are of a fictional character, especially if they can switch and/or posses. (2/2)

Thank you for the additional info. I’m not a tulpamancer myself so its really appreciated.