mmm, I don't know, there are examples, like one friend who told me than in 98um he never picks ex yuri and eiji because he feels than both characters play similar, then there is all the factor of those characters who are used just to earn stocks, and later the ones that will use those stocks, and so and on, there is also all the factor of counter picks
About pick the high tiers, I'm not so sure about that one, at least in 2002um, 98um, and in a lesser extent XIII, you can still see teams beating high tiers teams without using the 2 or 3 gods of the game
I could see both points actually.