Yes and no.

Firstly, even embalmed corpses weigh a fair bit.

Secondly, zombies are needed to kill certain classes and players. So while necro can I'll others he will be disadvantaged against anyone who needs zombies to be killed.

For example, my characters are typically going to survive sleep, but they don't survive loosing their weapon at the tail end of a non sleep fight. And it always happens to me at the tail end because I cover against stat loss well.