I am an outsider (never a dub), worldly (very), and so my views and opinions may not count for much.
When Russell started his religion (at a time and in a place where many new religions were kicking off) he was 'locked into' the 'science' of the time. Archaeology had not been accepted as a 'science', many thought - following Usher - that the world was 6000 years old, etc.
No problem - except for religions which taught (and still do, as far as I am aware) that their god was omniscient, all-powerful, and never changing. Whoops! Always big problems, of course, trying to reconcile the killing, raping, pillaging god of the OT with the Pauline liberal stuff in the NT, but as far as Russell and other loonies of their time (Smith, to name just one) were concerned they could speculate away 'safe' in their knowledge that nobody could contradict them.
Now we can - and the contradictions will only increase as scientific methods are developed.
To me, it's a bit like DNA - we can go back to 'cold cases' and re-investigate (cf. the poor bugger just released in the UK after serving 27 years for a murder he could not have committed).
If I was Mr Russell today, starting a new religion, I'd be a bit wary.