I don't know about other swarm players, but having consistent and clear markings for my ships is very beneficial to me. The less brain power I have to use during the day to remember which is which, the better I am at the end of the day. A big improvement for me compared to 5 years ago is the introduction of the color matched dials and ship bases (not sure who introduced that first but it is brilliant!) and the new practice of keeping track of the ships that have engaged with their dials. At the end of the day it makes a real difference.
That said I remember from my 40K days that some players deliberately used larger/more ornate models for the more expendable units in their army to confuse opponent target priority.
All is fair in love and wargaming? That said, it's much more likely to confuse less skilled players than high level players so I dislike it in principle. Don't club baby seals?