[France? That name kinda seems familiar... Though Hope cant put his finger on it.]
Each leader has their own specialization, but while it seems like a good idea to fill your party with Pokémon that have the type advantage, it's always best to have balance, as there's always a chance that the leader will surprise you with a move that exploits your own Pokémon's weakness. However, you can also do the same thing to them, especially with moves that have been learned from TMs and/or HMs.
It's also a good idea to be very prepared with your supplies, because given the chance, they will use healing or supportive items, especially in the last parts of the battle.
Lastly, you may want to create a strategy for dealing with them. After all, no two gym leaders are alike, and you'll want to learn as much as you can about them and their team before issuing your challenge.
text;
Each leader has their own specialization, but while it seems like a good idea to fill your party with Pokémon that have the type advantage, it's always best to have balance, as there's always a chance that the leader will surprise you with a move that exploits your own Pokémon's weakness. However, you can also do the same thing to them, especially with moves that have been learned from TMs and/or HMs.
It's also a good idea to be very prepared with your supplies, because given the chance, they will use healing or supportive items, especially in the last parts of the battle.
Lastly, you may want to create a strategy for dealing with them. After all, no two gym leaders are alike, and you'll want to learn as much as you can about them and their team before issuing your challenge.