Yes something like termux might be a sufficient addition to "android". Note a standard GNU coreutils build is about 15M, though one can configure to use a multi-call binary like busybox, reducing the install size to about 1M. See the coreutils-single subpackage in Fedora rawhide for example: http://pkgs.fedoraproject.org/cgit/rpms/coreutils.git/commit...
When you 'apt install coreutils' in Termux you get coreutils installed as a multi-call binary to save space. 1556 kB for the package in total (including man pages).
And what do you mean by "Linux"? Would GNU coreutils and a terminal be sufficient, or is there something else you need?