Now, I don't know how they planned it, maybe huge pokes like wailord, onix gyarados are special case, and the growth won't matter much.
Maybe Legendaries could only have one size. I have no idea.
I only give advice, take it or leave it.
I did my job, now do yours, a choice.
I'm weird, so don't take me too seriously, I'd feel bad for you.
Unless I say it, I never mean harm, it'd make me look bad if you think so.