When I split from my business partner 20yrs ago we did this.
We put all the cream work on a piece of paper, and then divided them on to two sheets of paper round 1 & round 2. These were divided so they balanced out money wise and time to complete.
We then did similar to the 12 wkly jobs. Then split the 8wkly and 4wkly jobs by days of work and balanced the monies within a few pounds. We also made sure that the jobs neither off us liked to do also were split fairly.
Then we stood back and said is there any round you prefer, and neither of us could pick one as they had both good and some awkward. If for instance we both wanted round 1, it would not have been a fair split.
In the end as we could not choose we put 2 bits of paper into a hat one marked round one and the other round 2, and we settled it like that.
Roy