3 PCs at the Same Time

I have 3 pcs A B C. left to right as typed.

I start A using PXE, then B then C. Whe I start the deployment A and C PCs reboot and B starts the deployment process. Is this normal? I thought they would all get imaged at the same time?

Also, will SD know to name PC A "01" B "02" and C "03"? As I image they should be incermenting their names.

Thanks,