The arguments of Hill, Jordan & Macphail (2015) are far stronger than the weak argument proposed by Heenan & Smissen (2013).
REFERENCES
Heenan, P.B.; Smissen, R.D. 2013: Revised circumscription of Nothofagus and recognition of the segregate genera Fuscospora, Lophozonia, and Trisyngyne (Nothofagaceae). Phytotaxa, 146(1): 1-31. doi: 10.11646/phytotaxa.146.1.1
Hill, R.S.; Jordan, G.J.; Macphail, M.K. 2015: Why we should retain Nothofagussensu lato. Australian systematic botany, 28(3): 190-193. doi: 10.1071/SB15026
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.