Leiter's always been played by different actors; well okay, License to Kill's is the same as Live and Let Die (for some reason), and the one in the Craig movies is the same.
I know, but when you have the one Bond with two movies, and his two movies are just a couple years apart, one of which is kinda sorta a reboot, and the other one has Felix as an important plot point, it really stands out comically.
The two Dalton Felix (Feli?) are also VERY different looking. Just to make it more surreal.
Like the guys in Goldfinger and Thunderball are both kinda older guys.
The Diamonds and Live and Let Die guy both kinda look sorta alike.
But the Living Daylights Felix is this real young looking dude. And then License brings back the Live and Let Die actor who looks pretty old.