From what I see, I will asumme you are not planning a competitive online team, but a Gen1 team to play the game right? Also, I’m asumming you don’t want to breed your whole team from lv1 (since you didn’t add the moves, natures or ev training). So I will only suggest Gen1 pokemon that can be strong enough for your playthough. If you are interested in a competitive Gen1 team it would be good that you also say which moves, nature, EVs and holding item your pokemon have in order to get a better rating and suggestions. I apologize if you already know about EV training and competitive teambuilding and I just took your post wrongly. I’m gonna try help you in the easiest way and if you want to build a competitive EV trained team from eggs and lv1, I will edit my comment and make it more proper.
Now, Mega Pidgeot could be a nice pokemon for your team if you are willing to train a pidgeot instead of the fearow. If you are using your parasect with supportive moves I guess it can work as long as you keep at a good lv (spore is a move you want in your parasect). As for Rapidash (Ponyta’s evolution), I think it really is outshined by Arcanine, he can do everything rapidash does, but better, but if you definitively want to use your rapidash, try to get heart scales to give her some coverage moves (it can learn poison jab and megahorn when you use heart scales with the relearner). With flare blitz, poison jab, megahorn and bounce (all from its own moveset) you can cover a lot of types and hit almost everything for at least neutral damage. For mew I have no suggestion since I have no idea how you got it, I thought the only legendary you could get was Thundurus, but well, mew is pretty strong and I would suggest to teach it stealth rock in selene town and give him a more supportive movepool. Snorlax is a good bulky pokemon with ok offensive capabilities, if you can, give him a way to set up (with belly drum, curse or any other setting up move you can get) so that he can sweep when needed. Then, change pikachu for another pokemon. If you are looking for an electric type, jolteon is a fast pokemon with decent special attack, it doesnt have a great movepool, but it is much better than pikachu as an electric type fast special attacker.
If you wanna build your team from eggs but dont want to deal with IV, egg moves, etc. Try to make a team that can cover its weaknesses, a Fire-Water-Grass core is a good start so Arcanine, Vaporeon and Venosaur are good options, then you can cover your needs with a fast special attacker like jolteon, a special defensive pokemon like chansey and fill the last pokemon to cover what your team struggles with. Good luck!
Please someone rate my team my team I beat water gym just now and I don’t have that much Pokémon because I only get the one I like but here I have a (lvl 33 marshtomp, a lvl 29 ponyta, a lvl 18 skitty, a lvl 32 amphoros and a lvl 40 klang. Is the team good I think so myself but just want to know your opinion rate 1 of 10.