Codger, you may be technically correct in what you say.

However it does not alter the fact that what many people actually sing is "Varsovania".

While Varsoviana may well scan, nevertheless, it is slightly awkward and does not flow comfortably - at least with the Dave Moran tune which is the one I am familiar with - and so when singing it gets altered - quite possibly unconsciously.

I have not heard the original tune but it may be that it flows better.

I was not trying to justify, simply trying to explain - a point you did not seem to get.