@Andrew-Staley , I hope all is well. I am glad that the MS-700 Teams Admin / Hands-on with Teams courses are proving to be helpful for you !!!
I spend ALOT of time discussing this exact topic with customers, and as you correctly point out, while there is no "right" way to apply a naming convention, other than what aligns with business process and policy, there are some considerations to be aware of.
The biggest issue/debate takes the form of ease of use/functional naming vs. security through obscurity.
What this comes down to is whether or not you want to name your infrastructure ( servers/desktops/devices/websites, etc...) in a plain and easily identifiable fashion ( I.E., MailServer1 ), OR, whether you want to use a totally randomized solution that DOES NOT imply or indicate in any way what the resource or site is designed or designated to do (I.E., PurpleUnicorn)
The issue/risk you are deciding to address here is what will happen when a hacker/bad actor gains entry into one or more of your systems and is looking to perform reconnaissance, in order to map out the network and figure out what target(s) to attack. The more information available to the bad actor initially, the easier it is to map out the network and to attack you BEFORE you figure out they are there and try and stop them.
If you are not too concerned about this issue, then use a naming convention that is simple to understand and follow, BUT, also one that allows for extensibility as you add resources over time.
The other major issue to consider is consistency. Regardless of the outcome of the discussion above, and which way you choose to go (random vs. exact description), you need to apply that convention consistently across the enterprise and stick to it. It will be very difficult from the inventory (asset) management/security/audit perspectives to have a half implemented sometimeish naming convention because it confuses things and makes it hard to have a complete understanding of what is happening, where, why, how, and to who or what.
If you have any additional questions, or just need help in general, please feel free to reach out directly as needed. My e-mail is: email@example.com
Good Luck !!!!