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I hate to sound rude, but thanks to team preview its pretty easy to predict a switch in from those. Even if the Roserade user fails to predict the switch the first time, the next time is a different story. So those specific mons are pretty shaky checks. Thats not to say you need a complete counter to Roserade or anything, but as checks go, there are much better ones out there.Sawsbuck is also faster, and easily KOs Roserade with double-edge at +1 (from the sap sipper boost). Most Magmortar are scarfed as well.
Swellow is probably a good answer as well, you can't be put to sleep while poisoned and Roserade would get absolutely wrecked by a Guts Brave Bird.