Co-op? I believe it can be done. If I'm a vibrational being right now and so are you, and we're both on planet earth, then why can't we exist on a different plane together at a different frequency??
"strong connection" ehh I guess it makes sense, but I wouldn't let Hollywood pervert your ideas on the possibility. Shoot, I bet people who are strangers to each other do this all the time, but they already don't pay attention to normal dreams as is. Who's to say that 2 well-experienced dreamers can't do this, even if they don't know each other? I won't be one of them.
Part of LD for me is exploring the phenomenon before even daring to label or describe it with little to no experience.