But consider -
ID1: Species A (wrong)
ID2: Species A again
Observation is now incorrectly RG.
ID3: Species B (right)
Observation is no longer RG under the current system.
With your proposal, a fourth identifier is required just to get the observation out of RG, which is unlikely to happen unless someone is tagged in by IDer #3. There are definitely tradeoffs involved, but I think it’s better to have more observations in Needs-ID limbo than to have more observations incorrectly RG.