Before I got modded, my limit was 4, because I didn't want to overwhelm myself. Now I just...watch over every club here like a Braviary. I have 4 right now, with a fifth one in progress.
In terms of limits, it's really up to you. If you want to handle 10 clubs at a time, go for it. I ain't stoppin' ya. But before you go for those 10 clubs, think about other priorities you may have, as well as the consenquences you may face. For better or for worse, it may suck up all your PC time. Learned that lesson the hard way tbh. Start with one in a slow manner and then start a 2nd one if you have room, and so on.