He's only 6'7" to 6'8", but the flipside argument is that a small guy with big length is generally going to be faster/quicker and better coordinated than a big guy with the same length.
CAN he adequately defend a 6'10" big?? That IS the question with Bennett. Good length and good muscle/build is a good start.
I must add the Bennett's numbers have dipped lately. Perhaps opponents are doubling him now??