I firmly believe that the skill level that one walks away from OW with is directly proportional to what they bring to the table. The more you've studied, and the more drills that you are able to visualize beforehand, coupled with the mindset to really learn how to dive, will give you a tremendous advantage over those students who are just out to get the card and just "get by". As you've found out...those divers are not hard to spot.
You should also be aware that some faltering students are really trying but just might need a dedicated buddy to help them along, and there's your chance to really shine.
I was the 5th student... the instructor paired me with them and told me why he did it later....