The problem is that Moldavia and Wallachia 1768 edition (for which the coins were issued) included both the territory of Moldavia and Wallachia 1859 edition (which, together with Transylvania, became Romania)
and Bessarabia, which roughly corresponds to modern Moldova.
(This is because Bessarabia was still part of Moldavia in 1768, and in fact since the 14th century; it became Russian territory in 1812, and thus was not included in the 1859 United Principalities or the 1866 kingdom.)
I've complained about the bundling of Moldavia and Wallachia, Moldavia, and Wallachia
in the Moldova WCC way back in 2016; however, in retrospect that might have been the best of bad choices - Moldavia has to be separate from both Romania
and Moldova (it could hardly be put under either), while Moldavia and Wallachia (1768 edition, as the only coin-issuing one*) does not really make sense under Romania either (though it's closer).
We could have put Moldavia and Wallachia under Romania, and we definitely could have put
Wallachia under Romania, but Moldavia has to be its own country (or under Moldavia and Wallachia, I suppose) because it's about half Romania and half Moldova, Moldavia and Wallachia
probably has to be its own country for similar reasons, and once that is accepted we automatically get either the current situation or a confusing mess.
I still have to admit that
Transylvania definitely belongs under Romania, though. I have no idea why is it (still) under Hungarian states.
*) aside from the one 10 ducat coin - and I do mean
one coin, as only one example is known - of Michael the Brave from 1600; I'm not sure what happened to the original, which is not on Numista, but
this is a modern type commemorating it