I was trying to not overcount. On higher-JS devices, it seems to be the simplest way to capture the following:

1. Not being logged in while reading an article (e.g., http://en.m.wikipedia.org/wiki/2008_Seattle_Mariners_season)

2. Tapping on the Add to Watchlist star and being toasted to Log in.

3. The browser POSTing to login and be returned to the article with the article being auto-starred (https://en.m.wikipedia.org/w/index.php?title=Special:UserLogin&action=submitlogin&type=login&returnto=2008_Seattle_Mariners_season&returntoquery=article_action%3Dwatch

If you're suggesting that action=watch is common even in higher-JS execution contexts, that may explain why so many apparently higher-JS UAs were also hitting action=watch bearing URLs (as opposed to sandboxed WebViews or something like that, although those certainly constitute some portion of such hits).

-Adam