The most obvious challenge is balancing the tension between rewarding the people who put Luxon in the job, while not tempting the envy of the people who missed out.
Everyone wants proximity to the leader and a good portfolio, but there aren't spaces on the front bench for everyone. Exiling disruptive MPs to the back bench makes for great punishment, but it also leaves ample opportunity to foment disgruntled rebellion.
Supporter Nicola Willis has already been given the deputy position and the number two ranking that comes with it. She's expressed an interest in retaining the housing portfolio which she has excelled at in the last year - there's a good chance she'll retain that portfolio.
Luxon decided to announce former leader - and leadership challenger - Simon Bridges' portfolios last week, neutering what would otherwise have been the centrepiece of today's announcement. Luxon has buried the hatchet with his leadership rival, giving Bridges sought-after finance as well as infrastructure and the number three position.
Expect a high ranking to go to another one of Luxon's supporters, Chris Bishop, (he's currently ranked eight). Luxon has said he wants to bring a more corporate performance-based approach to caucus rankings. Bishop has performed well in the Covid-19 role, and will likely retain it. Bishop will also likely return to his coveted shadow leader of the House portfolio - stripped from him by former leader Judith Collins.
There are question marks hanging over Collins herself. She currently holds the dubious honour of being the only National leader to lose the job following a no-confidence motion, which possibly precludes her from holding a major role. Her backing was necessary for Luxon to win the leadership, but she can't expect to be rewarded for this, given her virulent dislike of Bridges meant Luxon could count on her backing from the get-go.
But Luxon has also made clear he wants to draw a line under the past and let bygones be bygones, so don't expect Collins to be banished to Siberia.
Another question likely to be resolved today is what to do with former leader Todd Muller. Allegedly forced to announce his retirement by Collins, Muller has refused to rule out announcing his un-retirement - a trick pulled by his supporter Amy Adams last term. If he is sticking round, expect him to be given a decent portfolio and a good ranking.
Former deputy Shane Reti will possibly retain the health portfolio, and a place on the front bench, although his association with the Collins regime will probably mean a lower ranking to make room in the higher reaches of caucus.
Shadow treasurer Andrew Bayly will see his former portfolio extinguished, being rolled back into finance. He'll be demoted to make room for Bridges.
High-performing liberal Erica Stanford will be boosted. She's excelled in the Immigration portfolio this year, and will likely be handed a meatier portfolio and position in the higher reaches of the list.
Look for the divvying up of high-profile portfolios: education, foreign affairs, justice, transport, and social development.
Another question hanging over the list is what to do with the class of 2020 - MPs who joined the caucus following the last election.
This grouping is known to have backed Luxon strongly and could see some members rising up the caucus rankings (much to the chagrin of existing MPs who will be demoted to make way for them).
The class of 2020 is currently un-ranked, so anything is a win. Expect to see North Shore MP Simon Watts promoted for his work helping Luxon's leadership bid.
