The problem is that, for example, Lancer is an arrogant bastard who doesn't look like he likes to serve other people. And he's just a hero, not a *spoiler*. Archer is in a dimension of his own in terms of snarkiness. And others are more or less like that, with an exception of... hold on a minute.
Doggy lancer (I'm not terribly familiar with the rest of them, actually) honestly just wants a fight, iirc, and doesn't much give a damn about anything else. While he'd definitely rather be running around
kicking stabbing stuff in the face, the whole prana-maintenance means he's fairly willing to go along so long as he gets a fight sooner or later. That he listens at all is likely due to either the command seals hanging over his head, said maintenence, or, well... other influence, which I would kinda' expect given the situation.
The Hound is also not exactly what you'd call a traditionally heroic figure. Like, at all.
Similarly, normal Archer, is, well
not really a heroic spirit at all, and has a very different goal from most of the other participants, as well as being from the most independent class.
Counterpoints from the mainline, you've got both Berserker and Assassin who are pretty much in line without trouble ('zerker flips out in a fight, but that's mostly a class thing -- dude's fairly chill outside of it), and Rider who listens pretty closely despite kinda' loathing her main master
. Given that most of the folks involved
are just copies of the actual heroic spirit
I'd say it actually makes sense the system involved in the war is doing some subliminal nudging towards obedience, or at least cooperation. Most of the possible exceptions are either exceptions (Saber,
) or one of the classes that are capable of significant independent action (i.e. archer, which have it as a class feature, or caster, which are the most likely to be able to short-circuit the grail system). Most of the other ones (which make up a majority) are... fairly tame.
Least that's how I've seen it, anyway.