How is it possible that the two arrive at the same conclusion about a 'second century Josephus' writing in the same year 147 CE AND one does so through the name 'Hegesippus' (Eusebius) the other 'Josephus.' This can't be a conspiracy. The only answer is that they are faithfully reporting what was written in a common manuscript tradition - namely that a figure named Joseph who happened to be Jewish completed a chronology where all the numbers were calculated from the tenth year of Antoninus Pius's reign BECAUSE THAT WAS THE YEAR HE PUBLISHED HIS WORK.
There's no way around this. Someone published a chronology in the year 147 CE and both Clement and Eusebius report that that 'someone' was named 'Joseph' (a very common name).
It doesn't matter if Clement wore women's underwear or didn't pay his taxes or cheats on his wife or that Eusebius is a mass murderer, a liar or a cheat. They both independently report the same tradition WITHOUT KNOWING IT IS THE SAME TRADITION (or telling us that).
Stephan Huller has had a life long interest in religion and spirituality 
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."