IMO Bayman is the most popular Western character created from TN together with Bass, and his facial features are well done for representing a warrior. Maybe TN was lazy in their decision to use for the Western main character of Ni-Oh the Russian fighter's appearence, but I believe that the decision was got because they were sure that a such model could work without being too much risky.
Probably easier to reuse assests they have. Look at Honoka, she reuses Marie's face but a different wig makes her look different enough.
Besides, it's not overly obvious and non DOA fans will probably barely even notice if at all.
I don't know... :/ I usually don't use the complaint: "Developers are sooo laaazy! D:" Because they are not, they just often have a tight schedule and budget. This leads among other things to reusing old assets and that's perfectly fine... But reusing a well known face like Bayman's for someone like the protagonist of a completely new game, maybe even franchise? THAT must be lazyness and it is also quite bold if I may say so! XD