Test cricket and CC are not the same thing. I've actually not seen anybody claim that but feel free to misrepresent what I've said to "fit your argument".
Bairstow et al may be criticised at the Test level, not necessarily unfairly, but Bairstow - for example - has a pretty decent FC record for Yorkshire.
At no point did I say every single English player at IPL is an excellent red ball player, you wrongly inferred that, but it would be daft to the point of ignorant to claim that none of them are quality County Championship players.
As for Plunkett, no idea what the relevance of that is given that he's not involved in the IPL this year.