After the CL final I thought 'if only we had Gerrard', but thinking about it, he didn't get his team playing well in the cup final, he just bailed them out. Plus of course West Ham are hardly Barcelona. So any great player would have been of use really, though I suspect being down to 10 men would have been handy to have Gerrard's work rate etc...
People have been going on about Gerrard captaining England, but he didn't get his Liverpool team mates playing well against West Ham, so maybe people are being blinded by the fact he bailed them out... On the other hand Pires at his best used to get the entire Arsenal team playing well, making sure everyone got a touch of the ball etc, but you don't tend to think of him being captain material, even though he captained Marseille (possibly to keep their star player happy...).
So you could argue Pires would make a better captain, even though he's not exactly in the mould of Adams or Keane. Although rallying the team and mental strength are important too...