Since it likely also affects satellite orientation and possibly configuration. Also since brightness obeys a square law so they should ignoring effects other than distance be 1.5 times their final level still.
It appears that the objections are not to the size of the satellites (they are relatively small compared to other satellites in LEO), but that they are to be highly numerous. The planned size of the constellation is 11927 satellites.
The frequency with which these satellites photobomb astronomical images is the concern, rather than how much area they affect. In fact, their being smaller makes them more of a menace, as they will be more challenging to spot, or easier to confuse with an astronomical entity.
This said, I don't think this is a strong argument against putting such satellites in orbit, and progress will and should continue. Astronomers will have to be careful to avoid contamination.