That's where "useless" hublets like CLE come in. If you have 8 flights from some northeast city, XXX-EWR and 8 flights EWR-ZZZ, west of Ohio, an airline that wanted provide the same connecting options could interleave banks such that 4 connection opportunities go thru CLE and 4 thru EWR. Of course, they have to worry about the O/D traffic, but provided the frequency is reasonable, it doesn't have to be saturating.