Just a simple observation ,the WT used to say that their was an initial fullfilment of Bible prophecy and a later fullfilment for our day and that they mirrowed each other.
Do they still say much of the same thing ?
The initial fullfilment of matt.24:34 took place in well under 50 years from when Jesus gave this prophecy , A (one ) generation .
No overlapping of a generation occured then ,so none should occur in a later fullfilment of prophecy.
Their is no room in scripture , in the first Century of an overlapping generation of the initial fullfilment of Jesus prophecy.
No such thing occured .