The possible Talent Nimbleness seems to basically mean you only roll combat against one opponent and automatically avoid the additional opponents (upto 3) unless they also have Nimbleness. is that correct?
I think that Combat Reactions covers enough of this to be honest. almost to the point that I have pondered whether this Talent is a bit too powerful, one of my players has it and it has been a literal party life saver. given outnumbering players is one of the main methods of keeping low Skill monsters combative.
the auto ignore additional opponents seems overpowered. and you would have to check every single monster to decide if it negates the Nimbleness Talent which seems an excessive amount of work.
as for specific racial Talents, I quite like it thematically, but what this thread shows is that what it is to be an elf or dwarf varies massively from person to person even within the Titan setting.