It's fine to connect with people you don't know, but you never know how the conversation is going to go. If they send a custom connection request that you find appealing it'll probably be fine. But there's still a chance that person could: Spam you in messaging Add you to their email list without asking Message your 2nd degree connections saying
The biggest advantages to being a LION is that you end up with a high number of 1st degree connections, which ends up giving you far more 2nd/3rd degree connections. You may have a more irrelevant network, but you'll have a larger group of people that you can send connection requests to.