I've got no impression of
Ariana, because I've never encountered one (or a reference to one). So I suppose it naturally looks unfinished to me.
Mariana is Shakespeare and
Tennyson, but it's also inconveniently long when
Marianne is available. So, my preference would be, first
Marianne, then
Mariana;
Ariana dnf.
I should mention that there is practically no Hispanic naming where I live, outside a small Portuguese community who mostly use the names of Catholic saints as far as I can see.