Honestly, I do not really get non-SMA. I try to play all characters in a SMA compatible way. What makes non-SMA?
The non-placeholder rule applies on all islands, so technically this isn't a SMA matter.
However, if you want an application of SMA in that context, it's much more about the serious part. When you name a Lord, it's supposed to be for life. Yes, of course there are ways to remove him, but replacing a Lord is a very serious matter. You can't tell the Lord "just vacate the place for a few weeks please, I'll give it back to you afterwards". Being a Lord is not like having a job; if you're not a Lord you're just a landless knight. It'd be like telling a King "would you mind not being King for 2 weeks please?"