Apparently after submiting The Bryophyte Nomenclator to the curator forum and a botanist told me that this was probably the best taxonomy we could find for all families worldwide (https://forum.inaturalist.org/t/is-the-bryophyte-nomenclator-a-good-source-for-bryophyta-taxonomy/39125/3?u=victor_85), so I began a huge work of revamp of the bryophyte taxonomic tree, which needed it because there is a lot of missing species and duplicates/triplicates of species in different genuses. I also found this little book review article :
https://sci-hub.st/https://doi.org/10.1600/036364413X670223
which talked about the fact that Arrhenopterum heterostichum was in fact Aulacomnium heterostichum, but if there is any other sources that states about the fact that Arrhenopterum heterostichum is valid, well we'll go back !