Another bit of trivia is that through the pernament affliction bug, dwarves who have been coated in semi-pernament afflictive cave spider bites & forgotten beast extracts will also carry the debuffs with them, but this will be less important for anything but protection if on other squad dwarves as only the militia captain actually puts in any skill rolls into leadership, tactics, ambushing & social skills for extracting tribute. (im still investigating the last one, multiple factors like a basic strength check may apply instead)
Being focused makes dwarves fight & perform better (more achievable in the latest version, sermons deal with prayer need, rest are self explanatory for spending some time off reading books, getting new civvie clothes, dancing, drinking), so a well relaxed squad leader is always beneficial, as well as a relaxed entourage since training and being able to visit offhand amenities in a clearance of schedule will make the protection tighter.
If we can rate it in trolls slaughtered per minute.
Nil - Unconcious, dead, vampire with arms and legs ripped off by troll unable to die
T T - Dizzy, drowsy (from keeping a dwarf awake with loud noises like instruments), nausea & vomiting, exhausted, m-captain is a novice
T T T T T - Focused, well equipped, preferably assigned war elephants/hunting elephants based on mission, veteran leader
More about focus here, upper echelon of 'Very Focused' is currently un-attainable unless your dwarf is very easily fufilled with a narrow set of easily meetable needs. (unlikely)