I don't know why they don't play St. E since they have a healthy rivalry in football, it makes sense to play in lax as well. I know Delmar isn't afraid of the travel. The only reason I can tell is that maybe their schedules didn't match up as far as a date. Last year Delmar also had Appo and St. Georges, but they are not on their schedule this year.
I have heard of some teams shying away from Delmar because of their rough play in previous seasons. Like I said earlier, they are evolving from football players with sticks to an actual lacrosse team. Tough to do at a small school without a lax tradition. A young team, hopefully on the rise with probably 6 sophomores and a freshman starting. All however, have lots of lacrosse playing experience.