If there are relatively few delegates, and if they could each store their votes in single addresses, this could save a significant amount overhead for the network as a whole during voting/checking.

I suppose stakeholders by definition have an incentive to delegate their votes in such a way as to minimize the overhead in the network, but could this alone lead to some stable equilibrium?

Maybe you could also cull some necessary amount of the least influential addresses in the vote in order to help to reduce overhead to a workable amount?

I'm not sure if there's a transaction signing scheme to deal with retracted votes though, so I don't know if such a delegated voting scheme can even work.