Asking if you would avoid calling an sp 1MyProc, the simple answer is yes, because you can't do it.
But you can do it - I gave you the syntax.
Whether you would want to is another matter of course, and partly comes down to house rules (applying which my correct answer would be 'none of the above' as we call all stored procedures 'usp_xxx')
But you've corrected the question now. The question wasn't should you avoid "Create procedure [1Myproc]", it's "Create procedure 1Myproc". With the same respect i could therefore say that "sp_MyProc" is ok, as I've fixed the name and used "usp_MyProc".
If we follow this train of thought, and say that [1Myproc] is ok, is it really? The reason sp_MyProc is should be avoided is because it's bad practice, and could clash with an existing System sp. The reason you wouldn't use [1Myproc] is because starting object names with a numeric is bad practice, and so should still be avoided.
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does.