Browsing through some of the comments in /t/reclaimtribe, seems that it takes a few months of inactivity for a chief to be displaced. So I see the reasoning behind someone who is more active for a longer period of time before they take over a sub. Not sure how often this could happen, but you could have a new member claim a tribe, lose interest in the site in a few days, and still be chief for months to come.
Browsing through some of the comments in /t/reclaimtribe, seems that it takes a few months of inactivity for a chief to be displaced. So I see the reasoning behind someone who is more active for a longer period of time before they take over a sub. Not sure how often this could happen, but you could have a new member claim a tribe, lose interest in the site in a few days, and still be chief for months to come.
That is a problem, and one that I am actively dealing with myself.