Yes, Exo, the mic'ing technique is correct for orchestra recordings. However, the more people in the group, the more condensors you throw up. for a small group, say +/- 20-50 players, you'll have a pair of LDC's on either side, and then spot mics wherever you feel (soloists and such). The bigger the group, the more pairs of overhead mic'ing. With spot mic'ing the soloists, you really don't even have that mic's track up that loud, because the soloist is still in the main OH mics, so you just blend in the spot mic to just give it a little nudge, thats it.
Orchestras and metal bands are two totally different things to record. Metal is probably by far the most difficult in terms of mixing and getting tones to go well in the mix. Orchestras have all the different instruments in the range, you have the lower toned, deeper range instruments all the way up to the really high range instruments...there's no mixing involved, it's done "for you". With metal, like Jeff said, you have all this chaos and you have to make it all fit together nicely and clearly.
~e.a