This question is regularly asked to E2 visa lawyer.
If this question is answered “literally", the answer is no – the lawyer is
not required to obtain an E2 visa. On the other hand, his personal answer to
the question is – it is not compulsory, it is indispensable.
Indeed, an immigration lawyer, ideally certified in
immigration in his state, will not only help you and save you time as he
usually introduces this type of application...