I really don't know the anser to this one but I hear you Don C - perhaps the motivation for Rocco being sent on this suicide mission was that he was still in trouble for the deaths of the Tahoe assassins? You remember how sharply Michael said "Rocco! ALIVE!" and oops they turned up dead.

I don't mean necessarily that he was responsible for their deaths, as I sincerely doubt Mike would have kept him around had he suspected any guilt on his part, but perhaps this was one of the ways in which Rocco was expendable and Neri wasn't.

It still strikes me as bizarre that a capo would be sent to perform the hit, when they have a ton of soldatos who would be much more appropriate, but maybe from a dramatic POV it's to show that Mike by the end of II has isolated himself from everyone except the cold, murderous Al Neri and Connie who's got nobody else. Even Rocco and Hagen were out. Part of the tragedy, methinks