personally, i didn't feed kitten to any of my last three [not after Firefox got to a healthy weight]. i had adult cats in the house, i'm gone all day at work - just wasn't feasible. Java, height/length wise, is as large as Pixel - just not as cobby [more oriental body type]. Cable's a bit smaller, but cobbier. Firefox is still the smallest, but she's only a year old - i expect her to put on a little more size. but she was so ill her 1st few months of life that she may always be a smaller cat.
i felt as long as i was feeding a high quality dry & good quality wet, [with supplements for Firefox for a while] that they'd probably do ok... & they did!