While yes, you get more waitlists, it doesn’t mean you get more to replace night for trips on the other membership.
So, I have a January trip booked on one and my Feb trip on the other membership, I get to put waitlists in for each of those trips.
However, if I want to have more than two waitlists for the same trip, I’d have to actually double book it on each membership in order to get more than 2 in place for the same trip.