Daisy chaining two Lacie Rugged external hard drives

Hi there, 

I'm about to start a new video editing project using Adobe Premiere, on my 27-inch iMac with Retina 5K (bought in May 2018).
My video project is HD.
I've just bought two identical external hard drives for the project. Lacie Rugged Thunderbolt USC-C (2TB each).
I would like to daisy chain these two hard drives for this project, so that everything I do is constantly being backed up from one hard drive to the other as I go.
I have a USB port if that's helpful.
I tend to be shoot new material all the time while editing, and adding that to my hard drive as I go. So I need that to be automatically added to the second hard drive when it's added to the first.
If someone could please explain to me how to set up the daisy-chain from beginning to end, and the workflow thereafter, I would be very grateful.

Here's the compatability spec of the two external hard drives:
Interface: USB 3.1 (USB-C)
Works with: USB 3.0, USB-C, Thunderbolt 3, Thunderbolt 2, Thunderbolt

Spec of my iMac:
IMAC 27"/RP575/CTO
PROCESSOR 4.2GHz QC I7, TB up to 4.5GHz
MEMORY 8GB 2400MHz DDR4 - 2x4GB
STORAGE 1TB FUSION DRIVE (32GB FLASH)
GRAPHICS AMD Radeon Pro 575 w/4GB VRAM
I added 2 x 16GB DDR4-2400 SODIMM Memory for Mac


Thanks in advance,

Charlie