Zero is either a businessman attempting to look like a pilot or its off duty crew attempting to look like passengers.
One? Dunno.
Two - Depends on company. Can mean Second Officer or First Officer without ATPL or junior First Officer.
Three - First Officer or sometimes Senior First Officer.
Four - Captain
Five - dunno, doesn't exist does it? (or perhaps refer to zero)
So as long as there is one "4 striper" and either 2 or 3 stripes in the other seat, you'll be fine. (Note: I didn't mention two 4 stripers flying together. Eek, scary.)