With archaeological finds coming in almost everyday thanks to the Portable Antiquities Scheme recording local metal detector finds, it is critical to stay on top of new theories. Every now and again of course a major find comes up, leading to an in depth dig and potential paradigm changing discoveries. When this happens, it is the responsibility of any reenactment group worth its salt to change equipment in response to new evidence.
This happened to Dumnonika last year as we discovered contact with a lady running a PhD on Iron Age spearheads. It wouldn't be right to go into much detail until said work is published, but suffice to say that we discovered our spears were not accurate and needed changing. All this can cost money, of course, but the whole point of what we do is invalidated if we're not prepared to keep up.
Recent finds in the South Hams of early Claudian coins (i.e. invasion period) have led some to suggest that our theories of how the Romans dealt with the South West may be up for review.
We await further information with bated breath...