Resize posters for print in Illustrator

Hi,
I'm new to this forum and illustrator/photoshop etc.
I have created some poster designs in illustrator (over 200 different designs) I created them all using a template for bleeds and safe zones etc for printing currently at Size A0 = bleed. I was wondering if there is a way to "batch" process my designs to different print sizes e.g A1, A2, A3 and A4. Each poster contains a background colour, text and a traced graphic. I have tried creating an action but the properties I enter to scale down the image don't change and the result is often very distorted from the original.
Please bear in mind I am a novice when it comes to illustrator so please keep could you keep any jargon to a minimum.
I would really appreciate any help/advice you could give that would save me having to alter each poster individually.
I am currently using Illustrator CS6 but do have Illustrator CC 2019 at my disposal (at work) should it make any different to the way I can process this predicament.
Thanks again.
Regards

Steve