Duplicate content on wikis should almost always be handled through templates and transclusions, but in the case of the appearances templates, I preferred visual mode editing over the duplication-avoiding method of using templates, so the appearances charts remain accessible to new contributors. During the airing of seasons one and two, the appearances tables were updated in large part by anonymous and unregistered contributors, and new contributors often started their way the wiki by editing these tables. Without a template, every page needs to be updated individually, but since there are so many pages with appearances tables and the change is repetitive, this task is suited for a bot. I use Pywikipediabot through the bot account SweetieBot for updating the appearances tables. among other things. Pywikipediabot can use regular expression matching to quickly alter multiple pages. Anyone can request these sort of changes on the bot to-do list on the forums. If you ever need to make a lot of similar changes over many pages, add a to-do item to the list! Contributors who run bots often read that page and perform the requested tasks.
The command that updates the season three table headers is available here.