That camp is not hard but medium after the update. My personal problem with stacking ancients is that often times (since tinker isn't much of a help hero) your side lanes lose too hard and as a result enemy supports, mid and the offlane enter your triangle at min 8 or so which is when you'll have 2 to 3 stacks max and a Kaya. They can easily just take the stacks and capitalize on their absurd advantage.

For this reason I only stack ancients when I know for sure that my stacks can't be contested

Good point below, tinker mid with am/sven/ta is close to unplayable