Great box players are always great field players. Great field players are not by default good box players. Basically in box you don't have space to just carry the ball all over the place and dodge. It's a very technical game where a team has to move the ball quick to get a shot. You also have to be a great shooter to score in box. 4x4 goals and the goalies have bulkier padding. It is a different game in those regards, but the US is about the same at both. Last cycle the US senior team got a silver in outdoor and a bronze in indoor. Lost to Canada and lost to Six Nations. Canada won both. For U-19s the current US field team is not at all likely to beat Canada, and the US indoor U-19 team was 4th at worlds. Lost to Canada and lost to Six Nations. Canada is on top now in both field and indoor for both senior and U-19 national teams. The US is about the same level below them in both and the US is give and take with Six Nations. Right now the reason why Canada seems a little better is the box skill set. All the speed is the ball being passed around and not the players running around.