The Discovery design is superior to McQuarries. Where did you find the bottom design. That actually kind of makes me like it. THe problem with McQuarries is that the saucer is way too small compared to the main hull, the nacells are too small and both the nacelles and saucer raise up gracelessly vertical when you look at it from the front.
The engines are the "legs" or "wings" of the ship. You need big legs to run quickly. McQuarrie's engines simply don't look capable of streaking through the cosmos. The saucer is way, way too small compared to the drive section. Like why even bother with it? Actually, an arrowhead hull with nacelles wouldn't be that bad. McQuarrie isn't bad, it's just that his work could all use additional love. Like how Vader's mask needed refining from those original organic angles or how half of the ships in Star Wars (X-wings, Y-Wings, Falcon, Vader-s TIE, Victory Star Destroyers) are just ugly.
Anyhoo, at least the Discovery has powerful engines,