My brother is a botanist at U.C.Davis, where he does a lot of work
on Oak. In a conversation with him, he mentioned once he was doing
some studies of oaks in different locations, and part of this involved
grafting. So it can be done. I've tried grafting citrus and have not
been successful. It may be in part an art (or at least learned) so
you may want to get a pro to do it to maximize your chances of success.
B
P.S. In conversation with Michael Chamberland, he informs me that recently
someone has reclassified _Martyniaceae_ as _Pedaliaceae_. I am not
familiar with this latter family.