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 .
He has also published an article on medium about his experience drawing these units. Read it here: https://medium.com/@titos2k/few-lessons-learned-after-civ2-units-project-97f7ce63aa64
Discuss these drawings in our forum here: https://forums.civfanatics.com/threads/marvel-at-tomasz-zychs-civ2-unit-drawings.673910/