The 319 ranking for George Mason does not include their wins over Penn or Norfolk State. When GM has only played 5 matches, not including 2 will take a big hit. Penn is a decent win. The Ivy League has no sub-300 finishes in recent history and Penn is typically not the worst team in the league. Based on this, I don't think GM is a sub-300 team.
However, their remaining non-con schedule doesn't provide too many more opportunities for wins. They play Youngstown State this weekend at Virginia. GM really needs that one, but
Duquesne couldn't win against Youngstown State in Pittsburgh.
GM with only 6 wins finished with a 276 RPI at the end of 2017.