Group objects with armatures in one layer

I have A LOT of grass models with armatures and I want to move them all on a different layer because it slows down my scene because they’re animated. Is there a way can group all of them and then select the group and move it to another layer?
I tried parenting them all to a single one but when I move that one piece of grass to another layer only that object will move and not all of them.
Thank you.

If they all have a related name such as grassxxx you can use the Select / Pattern option to select them.

You can also use the Select / Select by type to select all the armatures.

or add them all to a group and select by group

When they are selected press M to move them all to another layer

Thank you very much!