That'd probably be their best bet! Bucky is shit at talking to ~fancy~ people, so he'd be better off posing as a staff member to hit up the working class (because staff members probably see and hear a lot just from working there and largely being ignored), while Steph could get closer to the royal family and go from that angle. That and Scott zooming around as Ant Man seems like a pretty solid infiltration.

And if they need the distraction, I'm guessing Enjolras probably knows a thing or two about starting political riots? I'm not entirely familiar with Les Mis :|a