Saying riders like Noval or Tosatto should have been replaced by someone else is easy now. But I think that at the time Riis had to make his choice, those 2 were the ones he trusted most. We also have no idea what kind of shape Cooke is in at the moment. Maybe Cooke didn't get selected because his shape was even worse than Tosatto's? And Larson is reported to not being your perfect helper at times and you need guys 100% dedicated to Contador. So it isn't like Riis had many options.
Also Contador lost no time so far that can be blamed on a lack of support. He was behind the fall in that stage, things like that can happen all the time. Maybe he should have been further to the front, but that is his own mistake. Even the best helpers available wouldn't have been able to avoid the time he lost after the fall. Now maybe he wasted more energy than he should have, but it is hard to tell if he would have done better with other helpers.