This is a good point, I never noticed the totodile's strongest water STAB is locked late game lol (also made me remember that liquidation is widely available in gen 7)
Gotta remember there are other fire types available like Arcane and I think houndoom if I'm not mistaken. They're good alternative choices if you start with a water or grass starter. Just like how Roserade is available if you use a fire type
You're underrating Charmander a bit imo. It gets access to 2 Mega evolutions late game for diversity, and even a regular can hit extremely hard and may be the biggest non legendary beneficiary from Sunny day with the solar power boost.