[duskwuff]

> DoTA games definitely stall...

That's been in flux recently! Patch 6.81, which was active from April 2014 until a few weeks ago, devolved into a "deathball" meta which tended to end games early. (This was responsible for the rather anticlimactic conclusion of The International this past July.) Patch 6.82 introduced some new "comeback" mechanics, which generally enhance the ability of a team that's playing from behind to recover after taking a teamfight, or finding high-value pickoffs. The details are still being tweaked, but so far the result does seem to have been less one-sided games, both in amateur and pro games.

And yes, "team stealth" is referring to Smoke of Deceit. A really interesting item, available in limited quantities, which allows a group of players to become temporarily invisible and sneak around the map -- even under sentry wards, which usually reveal invisible heroes! -- until they close in on enemy heroes or towers.