Help with my setup

I thought with a new edition and rules I might try a new setup, especially with the new models being released and I wanted to try a Mei shoota style.

Ofc I got myself 2 meks
But here’s my problem of understanding

Meis have the “support” class/ main category and the app said I must attach them to a unit.
Google is mixed with different answers and now I’m not sure if I can use them solo
Or not.

Thanks for your help and advice:)