It probably came down to money. Like Nick Locarno being renamed Tom Paris for Voyager, Macet was likely renamed Dukat to avoid having to pay royalties to the writer of "The Wounded" every time the character appeared on Deep Space Nine.
I'm not so sure. If you look at Paris and Locarno, the appearance, speech, and mannerisms are all identical between the two characters, even the backstories. If you look at Macet and Dukat, though, their appearances do differ somewhat,
and their speech and mannerisms (despite being played by the same actor) do differ pretty significantly.
Macet does not display any of the arrogance Dukat does; he's in a bad position and having to cover for his government's duplicity, yes, but he only shows anger as a result of Picard's incompetence in dealing with the situation--and even then, you can see him remove himself from the bridge at one point to keep from exploding any further...an act of restraint Dukat wouldn't have had in him. Macet speaks much more softly most of the time and when it comes to body language, you don't see him parade around and invade people's space the way Dukat does. Rather, Macet has more of a direct, military-march sort of mannerism that comes off as strong but not as
posturing.
