Zombies gaining modlels

[Ellisrich]

If a unit of zombies gains models from the newly dead ability and one of these models dies.

Can it be returned using deathly invocation or legion innumerable?

Also if the unit is brought back with endless legions does it come back with the unit size of what you paid for or the unit size plus the models gained from the newly dead? 

[Fluttershy]

The Newly Dead:

At the end of the combat phase, roll a dice for each model slain by this unit. For each roll of a 6, add a Zombie to this unit.

 

The Ability adds models to the unit, so I would say yes to both questions. Returnable & full (new) unit size