Thomasz Zych, or Titos2k on Twitter https://twitter.com/titos2k , has drawn all the Civ2 units in a very nice style.
He has uploaded them to his website, https://rysownik.com/illustration/civilization-2-units/ , and you can find a high-res version of the drawings also here https://rysownik.com/wp-content/uploads/2021/10/fullset-2.png .
These just look great!