GlobalDataStores and OrderedDataStores are different though. Certain request types adhere to different per-minute budgets and their use cases also differ. The former is used for storing all kinds of serialisable data while the latter is only for 64-bit integers and intended for ordered saving.
Roblox DataStores are sufficient enough for almost all data saving use cases, especially now that they support more storage in them. You should typically stay away from external databases unless you absolutely need tooling and integration that can’t be provided by using Roblox DataStores and said integrations are critical for your game’s experience.
When it comes to avoiding data loss, it’s all about working around the budget: getting the most out of a few requests per player. Frankly you can get away with any kind of setup and you’ll be fine, you don’t need the backups method (that’ll be natively supported in the future anyway). It’s important to battle test these solutions after developing them.