Having one of two fast drivers disgruntled is a huge difference than the behaviour Alonzo is displaying. He is DEMANDING (and blackmailing) that he have #1 status, based on his performance at another team in a different situation, just because a rookie who he didn't count on having much speed turned out to blow his doors off the first few races. Who is to say that Lewis wouldn't have trounced him the last two years if he had been in the McLaren earlier? Then what status would Alonzo have expected? No, if he was simply unhappy and just shut up and raced, then there would be no problem, but he wants to screw Dennis simply due to his feathers not being primped enough.
I question if Nico has any such status at Williams - I think Wurz has the higher salary, which usually indicates 'status' if one can say there is any such thing at Williams. He is simply #1 because he has more points, but I doubt he gets any special treatment.
Button may be under-rated, but after what Ron just went through and knowing Button's past bahaviour between Williams/Honda/Richards, I doubt Ron would touch him. The last thing he needs is another whiner. And 'fairly fast' doesn't cut it at McLaren...would he be any faster than Pedro? Who Ron could stick in the seat for a pittance? Not saying he would, just that he could.