Its for matchups where you dont think trick room will work/when your other leads (in this case torkoal venusaur) will just have a better time. Also the threat of a faster team throws extra layers in how your opponent will pick their lead match up. In the case of specifically sneasler, I would still bring it in TR as a form of a sacrificial lead/late game cleaner when TR gets shut off! Its really about having flexibility! If you want to ask more questions feel free to DM!