Both companies can be all over the place when it comes to grading the AB's. I think at least with today's grading it has to do more with what they see on the edges than what the size is. In general the 460's are a little smaller than the 350's.
There are several good examples of smaller than normal AB's receiving grades in this thread. Take a look at Ted's Frank chance in post #22 of.
Ted also cracked out a Jennings (post #92) from an SGC A holder and had it graded by SGC again and they graded it an SGC 60 (post #138)
https://www.net54baseball.com/showthread.php?t=158706