It could have worked.if he had made the movie in yhe early 1990's, certainly not later then 1995. An important aspect of the comics is the 1980's cold war mindset, the idea that it is 'five minutes to midnight' and the Great Nuclear Exchange could blow us back to the stone age any moment. As much as I like the OTL movie, it just came out too late, to be watched by a generation that never got the meaning of the song '99 Luftbalons' playing in the background at the first meeting between Night Owl and Silhouette.
Bonus points if Gilliam mamages to.release the movie in 1991 either during or just after the first Gulf War. OTL Nato and half of the former Warsaw Pact ending the cold war by joining up to clobber Saddam Hussein might bring unintended poignancy to the book/movie plot of the US and Russia ending the cold war by uniting against a makebelieve threat from a makebelieve alien space monster.