Clonezilla is a disk imaging tool and system cloning tool. It can use CDs and DVDs, but shines when used with a LAN, to clone multiple computers from a single Clonezilla server. It’s a little arcane, and you should dedicate an old computer to be your Clonezilla PC. Anything Pentium 3 or better (meaning a 20 year old computer), can be your server. The system is open ended and flexible, but that comes at the cost of complexity.
I’ve done cloning operations with more than 20 computers at once. That’s a kind of practical limit, for one person, because the time required to walk to each computer and press keys, and monitor progress, increases to the point of diminishing returns. If you can cram the computers into a smaller space, you can clone more computers. Below are the articles about Clonezilla. They basically reflect the instructions provided for Clonezilla.