better Gemini Mans?

Will Smith dosnt look all that different now from how he looked in Bad Boys/ID4.. the FX team must've breathed a sigh of relief when he was cast! lol (in fact maybe that's why they went with Smith as the difference is almost negligible )

I'd have gone with one of the original choices when the movie was 1st announced in the late 90s - Mel Gibson vs how he looked in the 80s (Mad Max trilogy, Bounty, Year of Living Dangerously). 2nd choice would be Stallone vs 80s Sly (First Blood, Rocky III). The FX team would've been had to be working around the clock on those dudes! (plus either of them were like the original action stars from the 80s whereas Smith started in the 90s)

The other original choices wouldn't have worked now as Arnie and Bruce have already done the v's younger self thing (Terminator 5/Looper) and Harrison and Clint are now too old to realistically play hitmen (they'd have been good in the late 90s along with Connery when Gemini Man was announced but then the CG wouldn't have looked right).

other 90s action stars (like Smith) such as Cage or Travolta could've worked but they've sort of done something abit similar with Face/Off and neither are very bankable in the cinema now (mainly do STDVD stuff now).and Keanu? Cruise? Pitt? it'd be almost the same as Will Smith - they've barely aged! of course any of those guys are still huge in the cinema and starring in current blockbusters where as all the 80s guys like Mel/Sly don't appear all that much now/not so bankable unless its a return to one of their iconic roles. The appeal of doing the older action star vs younger self is to see them in their prime again on the big screen, so when it was announced in the late 90s it was the action heroes from the 80s and even before like Clint, Connery, but now I guess it makes sense to have got one of the 90s action stars