I'm pretty mad at zArchiver for cutting of the top of every file extracted from iso.. Try using tar in terminal on tablet and see what it does. If you have an Y otg cable you can also do install it from a usb stick, abd then try if your rootfs unpacks well and eventually upload it. This tutorial was meant to be useful for people withrout y otg, too, but if you have one it's not that hard to install it yourself.
Press f2 while booting, choose flash drive , select install, custom mode, just select sdcard as rootfs (no data partition doesn't work) and install. Then grep dmesg for a missing txt file for wifi and use /system/etc/nvram.txt in it's place. Be aware it might rewrite your grub.cfg
about the file to extract, i tried doing it on terminal emulator, same error
ill leave attachment of the error.