The correct expected average is 395013.

For 10000 random ranges of size 2**70, 9999 of them will have between 392679 and 397353 such matches. That is, the probability to have a ≠ 3000 deviation is 0.01%

There are too many zeros for the probability to only find 1353 matches. It's more likely that the entire galaxy implodes today, than the chances to only find 1353 of those matches in a 2**70 range.