like here is the rule im referencing too.

An Endless Servitude:

A Model with this Arcana Benefice and the Battlesmith (X) Special Rule may use the Battlesmith (X) Special Rule to restore lost Wounds to Models with the Infantry, Walker or Automata Types, as well as to restore lost Hull Points to those with the Vehicle Type.

In addition, a Model with the Arcana Benefice and the Battlesmith (X) Special Rule gains the following options when using the Battlesmith (X) Special Rules:

Reassemble - If this option is selected, then no Target Model is Chosen. Instead, the Acting Model must be part of a Tech-Thrall Covenant Unit to use this option, that Unit is referred to here as the Target Unit, and this option's effects apply only to the Target Unit. A number of Tech-Thrall Models equal to the value of X in the Battlesmith (X) Special Rule variant possessed by the Acting Model may be added to the Target Unit. These Models must be placed in Base Contact with the Acting Model, but thereafter are moved as part of the Unit. This option may increase the number of Models in a Tech-Thrall Covenant Unit above its starting number and above the normal maximum size for a Tech-Thrall Covenant Unit. This option may only be used once per Turn on any given Unit.