...But in the Trek universe, these guys and gals are supposed to costume themselves. (Of course, they can make errors any morning while getting up from the bed with a slight hangover.)
Yeah, in the real universe, the odd pips are of course assorted costuming errors. What we make of the errors is up to us the audience, though. It's not that difficult to squint and see more than three kinds of Maquis pips, preferably so that the squinting removes inconsistencies.
It's a bit more difficult to squint at Tuvok's pips, because they are larger and easier to discern. Which is why I'd very much like to concot an explanation as to how he wore Lieutenant Commander pips for such a long time, and then moved to Lieutenant.