Hi! You're right, obelisk Defense is a part of the Total Defense. 

hi

i think total def is not calculated with legendary units but obelisk def yes

unless they have fixed it (highly unlikely) the oblisk defense numbers do NOT reflect the legendaries. also important to note if you send all your legendaries to OB but don't include supporting units they don't give full benefit even if your other clan mates have sent thousands of the supporting units. YOUR legendary YOUR units for support.. also their seems to be delay in stat changes as far as ob defense reflecting losses incurred recently so that also may affect the numbers displayed and its accuracy