For two people and hourly releases, I’d keep four:

The change says how it ships. Steps and a rollback written on the ticket, not in someone’s head. Ours is a sub-task Jira creates from a label. The other person reads it. A real review of the steps and the rollback, not a click. With two people, that’s the whole review board. Tests that check behaviour, written while you’re in the code. Not coverage padding at the end. One check after every release that someone owns. Automated if you can, named if you can’t.

Everything else (CABs, multi-level sign-offs, freeze windows) earns its place as the team, the systems and the blast radius grow.

And the list isn’t fixed. Watch for friction and talk about it every sprint: if nobody can say which failure a check prevents, it’s red tape, and if something keeps slipping through, you’re missing a check. The right minimum for two people won’t be the right one at ten.