Since there has been no dissent thus far I will be committing. POWO does not directly state this synonymy, but GBIF does. The Plant List names V. cretacea as a synonym of V. lavrenkoana, and POWO lists V. cretacea as a synonym of V. hymettia.
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.
Since there has been no dissent thus far I will be committing. POWO does not directly state this synonymy, but GBIF does. The Plant List names V. cretacea as a synonym of V. lavrenkoana, and POWO lists V. cretacea as a synonym of V. hymettia.