User blog comment:The Milkman/Mass Effect in Retrospect/@comment-4721065-20130419132524/@comment-3228423-20130419222643

They couldn't send a recon team to go through because doing so would alert the Collectors that the Normandy was coming.

As for making the team, they just couldn't hire a bunch of random mercs with next to no skills. They needed a team consisting of the best people of the galaxy. The best tech experts, the best biotic specialists, and the best soldiers. And another reason why they couldn't just send in an army. An army is too large, too noticeable; a small, elite team is more than capable of infiltrating such a heavily fortified enemy base