>>28717859I got inspired by a different anon to try doing what you're thinking. My Greninja only has some experience fighting (he won the two badges I have before I put off the gym challenge for my breeding career). My Fletchinder is new; I'm not sure about his battle experience since he's been picking on weak Burmies.
Best you can try is test what level of skill your Pokemon are at by having them battle weaker Pokemon near you and then introduce them to stronger wilds.