TBH, once you start getting proficient, it is more normal to move away from integrating Assist and/or IWT into the single actions, and to separate them. This is so you can more effectively manage multiple targets, rather than have to focus on a single target all the time.
But, that said, assuming ISBoxer based on the terminology, your best bet is to create a second menu (or set of mapped keys in a different Key map), and have it call the IWT mapped key, rather than the Assist Me mapped key. The IWT mapped key already does the Assist Me as part of the process, so you don't need it twice.
There is a
video on creating a second menu, by duplicating the existing one, and then updating various values. If you are using mapped keys, then create a Key Map, then use the Mapped Key Wizard to create the basic mapped keys (or you could create Assist+Broadcast), and then update them to call the IWT mapped key first.
If using the Key Map, then you will probably want to assign it to the team, and add it to the Activate Maps mapped key. Also you might want to set a white/blacklist of Key Maps for that character set (so you don't get multiple key maps with the same hotkeys loading up).
If using the menu, you can set the Override button set for the Character Set on the Standard Menu, or you can create a whole new menu, and assign that to the Character Set instead.
