Well, then, it seems Warwicks fans of the '70s and '80s have misplaced misgivings.
Maybe he didn't produce 8-fors when the opposition was chasing 100-odd for Warwicks, but he still did better for them than for England. That's fact. Hence, the argument is bust.
I personally dispute very strongly that Hick was a major talent, probably the most talented county player we have seen for 30 odd years. I would say that he had one major flaw in his technique that was exploited by the best bowlers - county or international. I don't think it was anything to do with being unable to handle pressure at all. In fact, the fact that he was such a brilliant ODI player, a game that attracts even bigger audiences than the Test game, hammers that home even more for me. It was nothing temperamental whatsoever - it was all about a technical shortcoming.
Any player who's played the game in front of big audiences will tell you that none of that matters at all when you get into the middle - it all disappears. Tendulkar has said it countless times - if he genuinely worried about the pressure of a billion people's hopes hinging on him, far from not being able to play, he'd probably have committed suicide by now.
The game isn't black and white - but nor is it 4294967296 shades of grey or 4294967296 different colours. As some would have you believe.
Anyway, the basic point of the matter is, for every example of someone who failed at domestic level and succeeded at international level or vice-versa, there are many examples of those who did well at both. Aside from the "pressure" stuff, this is what matters.