The hotel has some pretty skilled individuals, powered and otherwise. If Rogers, Barnes, Romanoff and Gamora corner Brumlow then it's a done deal. Harry and Eggsy could definitely aid in cornering Rumlow but without weapons, I don't see them successfully capturing Brock by themselves.

Rumlow is far from a typical baddie. He went toe to toe for a good bit against Captain America. (Hence why as much as Trip would like to go after him, he knows it can be a fatal mistake to do it alone.)

And if everyone votes to keep Rumlow detained, would the hotel allow such a thing to take place? Would a room even be a good place to detain him? The only way I see him not escaping would be to have round the clock guard of powered people in the same room with Brock.

/two cents