Great Point is the broker dealer there. They have about 90 licensed traders. Tower Hill is a brand new LLC.
You don't need a license to trade under Tower Hill. Same place, just different licensing requirements.
Maverick Brokerage was forced to change its name by another firm called Maverick. They changed it to Great Point years ago.
Great Point is a broker-dealer running a prop business.
Tower Hill is a prop group hiring at the same location, but as a regular LLC.
Hope that helps.