The list of big men, or even reasonably big men, who have successfully played the point guard position in the NBA, or been asked to, is not - you should pardon the expression - a long one.
Ron Harper, Michael Carter-Williams and Brian Shaw did so at 6-foot-6, and Penny Hardaway and Shaun Livingston at 6-7. Oscar Robertson, one of the all-time greats, was 6-5, which was enormous for a point guard in his day.
Beyond that, there is only one name. As you search for comparisons to what the 76ers might discover in terms of advantages and challenges with 6-10 Ben Simmons as their starter at the point - which is the intention of coach Brett Brown - that name will be both a blessing and a curse.