I actually tried this with my previous version, where several other comics were tied into the main comic. I do not recommend it as it's hard enough getting readers for one series, and most readers will not seek out the connecting works. So you end up having to try to market several stories over just one and will spread yourself thin, inevitably with very very few people being interested enough to seek out all the connecting works. This is one of the reasons I chose to reboot my previous work, so I could condense it all into one work.
If you're perhaps a big name in the comic world like CLAMP where most of your work is well known individually then it can work all right perhaps (like with Tsubasa and xxxHolic) but otherwise I think it's a huge waste of energy and high risk for not much viewership.
Now a sequel or continuation series would probably have a better chance of doing all right if the original did well since the audience for that work is there more for that, vs doing side stories connecting.