the way military training works is probably the most broken part of fortress mode IMO. it should probably be rewritten to work better. obviously i don't have any insight on how hard that would be, but i imagine it wouldn't be too difficult a task; should just be a process of adding in a few checks to make so that the guys doing demonstrations are the most skilled, maybe boost the experience awarded for watching demonstrations of high-skill warriors, and making sparring more common. as it is training is horribly slow
I won't claim that it's perfect, but there are a few wrong or exaggerated statements in that quote.
1) I've never seen a demonstration led by a lower-skilled dwarf compared to the skill levels of the watchers. Just because someone who is Dabbling or Novice is leading a demonstration doesn't mean there is a bug. The guys watching may be even worse.
2) The amount of XP given by a demonstration is a function of the Teacher skill of the guy leading the demo, and the Student skill of the guy watching. The teacher's relevant combat skill may also matter -- I don't know that part. (Upshot: demonstrations do not totally suck.)
3) The amount of XP gained by training in 0.40 right now is IMMENSELY higher than it was in 0.34. This may be a side effect of the entire 0.40 skill-gain system being totally different, because
all skills are going up faster now, not just military. In which case, if Toady "fixes" overall skill gain, this may have the negative side effect of returning military skill training speed to 0.34 levels. But for now, training is very effective.
4) Once they start sparring at all, sparring becomes extremely frequent. You get literally dozens of pages of sparring combat reports per season. There is no shortage of sparring.