That is correct, Method 1 and Method 2 are similar, in Method 1 you have
got DTM and you can do that in DTM with few steps, without writing any
code to grab customer ID/ CRM ID. So these are almost similar, and would
allow you to use other functionalities, also Method 1 ensures the ID
sync before Target is loaded.If you have an eVar that is capturing CRM
ID and same call will have Marketing cloud ID, but still you would need
AAM's ID sync, so yes you would need any one of the Methods for ID sync...