Well that is very interesting. From Summon Monster, we learn which alignments Celestial or Fiendish creatures *might* have. Celestial creatures are good or neutral, and Fiendish creatures are neutral or evil. But it never tells you, conclusively, what the application of the templates themselves do to alignment.
I personally find it rather odd that a neutral summoner can summon up a Fiendish creature, complete with Smite Good, that is not evil itself. Then an evil summoner can summon up the same (type) of creature, and it's really evil this time. And each time, it's Intelligence is no greater than animal intelligence (1-2), so nobody understands how it is making moral choices. Meanwhile, the Advanced version of the same creature is somehow promoted to above animal intelligence, which specifies it could potentially speak (and implies a variety of other things), when the point of that template is to make it fiercer and more powerful.
I think this is an effect of rules that were not thought out in these areas, because it doesn't make a lot of sense. However, to cut to the chase, as long as it's allowable to call Fiendish animals evil (since some are) and to call Advanced animals stupid, I'll do that.
Just so long as it's not going to be a problem with the judges.