I think you have a decently rounded team. I would replace the munna and ariados with other mons like budew, joltik, or litleo. With where you are right now, you can get two eggs that have good chances of getting decent or strong mons like bronzor, frillish, ducklet, or cacnea. A bit later, you can breed a certain mon to also roll your luck with an egg that can hatch up to 18 different mons, most of which are very strong. But the one of the best parts of this game is that it teaches you to not limit your party to only 6 members, you can use any mon you like and just switch it out with a more suitable member for a certain gym or event then just switch it back.