There is a risk with so many people, but it turns out to also be a boon. With so many eyes and ears, they know to stop and wait, or backtrack a few steps to wait for a guard to pass by where they just were. It's painstakenly slow, but they eventually reach where Ratonhnhaké:ton and Jon entered, and now comes the task of helping these weak and tired artists onto the roof. Staying put for so long is a less than ideal, but if it comes down to it, they can keep climbing even if they are caught by one or two guards.

Maybe.

They don't have to find out, luckily. With some help, the artists get onto the roof, and Ratonhnhaké:ton and Jon can follow. From there, it's a lot easier. He's completely sure of where the patrols are (but they of course still proceed with caution) and can get them far enough away to get out of trouble.

Hopefully his patron can help them out now that they're out of there.