I need help understanding the order in which the netplan config files are applied and, if possible, how to set a fallback config.

**Scenario:**

* Let's say I have two config files, A and B.
* Config files A and B both set the same ethernet interfaces in
different ways. (different auth methods...)
* Config A file name is : 01-config.yaml
* Config B file name is : 99-config.yaml

**Question:**

1. Which config file will be applied?
2. Would config B work as a fallback if config A didn't work? Or the other way around? Or neither?
3. I want to set a fallback config file in case the existing one(A) fails. Is that possible?

Thanks