“Perhaps the extra girls on shidduch island should marry chassidim.”
Chassidishe boys are mostly looking to marry chassidishe girls. There are some shidduchim of Chassidishe boys with litvish girls, however, the boys aren’t usually your average chassidishe boy if they are marrying a litvish girl.
Which isn’t necessarily a bad thing, because litvish girls probably aren’t looking for your average chassidishe boy.