What's the difference between my five stories that have marriage as the centre plot?
So there's Married in Hogwarts and then the Sequel book.
Book one is completed and follows Hermione and Draco in their final year at Hogwarts and the first year of their marriage which they have to keep hidden from their classmates and friends. Its set one year after the Battle of Hogwarts. And the marriage being hidden is the main part of the plot.
Book 2 follows Scorpius Malfoy and his Wife, Rose Zabini in the middle of their school years also hiding their marriage except their friends all know but the rest of the school doesn't. It's set in 2016 and it's basically a slice of life.
Now, the comparison with ContractxMarriage and Duality.
Both follow a similar concept of arranged marriage but one is based around the anime SpyxFamily and the other is based on Avatar the last Air bender.
ContractxMarriage follows and aged up Anya and Damien after they get married and have to deal with day to day things as a media couple, whilst keeping Anya's power's hidden.
Duality follows a Zutara arranged marriage where Katara has to manage the trials and tribulations of becoming the Fire Nations Crown Princess whilst also trying to melt Zuko's icy heart without accidently giving away her own to the Blue Spirit hero who keeps coming to visit.
Finally, there's Stay At Home Katsuki, which follows Bakugo from My Hero Academia after he marries Uraraka and has a daughter who he has to look after whilst Uraraka rebuilds her career as a hero after being on maternity leave.
Hope one of these interest you.