pumping question

I feel like such a newbie at this! Lol. Does the shield size affecty how much is pumped? I know it's still early and I have a little time to get a stash but I pumped so much more with Kaitlyn! I think the shield I have is too big (according to the pictures on the packaging, so I am going to get the next smaller size and give them a try. So frustrating trying to figure all of this out again. Lol