Is having too much non-engine actually detrimental?

Everyone always says that having like 20+ non-engine is good because it's interaction on things like your opponent's turn, but sometimes I feel like you can open very awful brick hands every once and a while. Is it worth it running that many non-engine or is 15-18 enough in a 42 card deck? What is the golden number for handtraps/non-engine? Also what handtraps should you even be playing right now? Are Droll and Nib three-ofs in your main deck?