Does anyone know how the default pokemons are selected for the gym battle? Are they selected by type? By CP? It seems so random!
I just replace them to the highest CP, but wonder if that's possibly not the best strategy. One thing that is a bit annoying is that you start battling the weakest pokemon first, then towards the end your pokemon start being quite weak against the strongest pokemon in the gym, and so maybe choosing one 'winning type' pokemon against each pokemon in the gym is a better strategy?
It doesn't matter for level 2 or 3 of course, but becomes more important for levels 8 and up.