I think it varies between pigs how much they shed. I have two guineas that look very similar, they are both smooth and short haired. However, their hair shedding is very different. The girl has very fine, soft hair and sheds virtually nothing. The boy's hair is quite thick and bristly and he sheds a lot more. It's not like balls or clumps of hair that come out though, it's just little individual hairs that stick to your clothes a bit. I would say if you are accustomed to dog and cat hair, then guinea hair isn't worse or too much different than that, in fact it's a bit better because they are that much smaller! Definitely go for a shorter haired guinea if you are worried.