It is meant to be a Blockade of a relatively undefended planet so the ships would be enough to hold out that pretense.
I got the feeling that if the Chancellor hadn't sent Jedi the Feds would have carried on with the pretense and fobbed off the ambassadors until they had gone.
It's the Jedi the Feds are frightened of.
In a scripted line Sidious points out to the Viceroy that they seem to be more scared of them then they are of him (I wish that line could be put back).
Having a more empty hanger would add to the mystery of the scene, enhance the reputation of the Jedi as a force powerful enough to keep peace on a galactic scale and explain the Feds preference for droids (easy to mass produce as they are they have limited abilities as an armed force).
On a separate point perhaps some of the more silly PT names could be adjusted via truncation. For example General Gree sounds more Star Warsian and less silly than General Grievous.