Dolphins have confirmed they'll play an extra game at Suncorp next year (8), so that definitely helps.
They are still playing 3 at Redcliffe though.
As horrible as it sounds one thing that would help crowd averages is limiting 'on the road' games to bigger venues.
Outside of Hamilton & Perth, most matches taken away from the regular home games this year attracted 11K or less, below most teams averages.
The other thing that would play a significant role is preventing certain clubs from playing in certain timeslots.
For example, outside of anomalies like Broncos v Storm, both Suncorp teams drew significantly higher when playing either Friday 8pm or on the weekend.
Parramatta is similar, the upside of them not having Friday or Thursday night, was worth about 30%.
Titans have struggled to draw good crowds for day games, so give them night slots and the dreaded Mother's Day game (especially the 2pm timeslot) should not be given to clubs who can draw more than 15K.
Key derbies should be protected from being played at certain timeslot, ie. Don't play Cowboys v Broncos at 3pm on a Saturday, etc.
Rigging it a bit like that could make a noticeable difference to the averages, especially when the upside is an extra 10K+ to a game (Eels v Panthers for example this year would have sold out on a Friday, but instead got 17K on a Thursday)