Should I assume that the next thing you are going to say would be a claim that English and Irish on one side and Polish on the other are mutually intelligible? This is what follows from your words.
No, it doesn't. My point is that these things (language affinity and country of work migration) do not depend on each other. So all your next considerations are wrong
I suspect that when selecting between two migrant workers otherwise identical in their professional skills and abilities the absolute majority of employers will choose the one who doesn't need an interpreter. But you may, of course, choose to disagree...
And start to claim that Earth is flat and Elvis still alive
When I say that Ukrainians perfectly well understand Russian (and this is one of the reasons why the Ukrainian board is not a priority)
This is wrong too. Even if a lot of Ukrainians understand Russian it doesn't mean that Ukrainian board is not a priority. It's obvious, isn't it?
It is obvious that the Ukrainian board is not a priority. You may rationalize that fact whichever way you like