Kids don't have to be on a top team for their second sport to enjoy it; they could just play rec. Making kids specialize this young is ridiculous and leads to burnout. Some will come late in the fall to tournaments because they had a soccer/field hockey game or miss a tournament (day) all together. They are not being recruited for several years so let them have fun and learn commitment.

As an aside: There is a player at UNC on both the soccer and lacrosse teams. A few years ago there was a dual sport field hockey and lacrosse player at Penn State. A girl at Georgia did soccer and basketball. BYU had a girl do basketball and a volleyball. So who knows, maybe this is a dream for some girls.