If a site is over-submitted, maybe further submissions from that site shouldn't accrue karma to the submitter. That is: "No cherry picking." Articles would still appear and their placement still depend on votes, but there'd be no narrow personal value to submitting them.

Initial candidates for such no-credit status: TC, PG, 37, CH, XKCD... though the list could be dynamic based on number or popularity of recent submissions.

(Crop rotation for mindharvests?)