Persisted spells >>> free hastes. Plus, in epic you can easily do both.
Arguable. Extra actions >> a bunch of buffs (here I'm moving the frame of reference a bit: since below you're abusing GCF I'm guessing Epic Spellcasting as-is is in, which means the Swiftblade also has all the buffs he needs).
And, um, where does the cleric lose in that comparison? You need to pick the right domains, of course and get any of the spontaneous domain feats. Plus you forgot the most important spells: Permanent Emanation (Greater consumptive Field) and Persisted Owl's Insight (via Hierophant).
GCF is Evil and so not always usable (even some Neutral clerics will balk at killing live creatures to increase their power). The point is that the Cleric has to choose his domains (a limited number even with a bunch of PrCs) and only has a limited number of Miracles to emulate Druid/Bard/... spells : so he will end up losing out, whereas the Archivist can get Turn Undead easily - the most important Cleric class feature.
I guess the Artificer can come out on top of both of them.
Probably you're right with everything. The good guys get the shaft, as usually
.
However, I think with the tremendous power Clerics get already, the Archivist is just a small step ahead, just for convenience. I know too little about Artificers (due to them being Eberon), but I guess you could be right about that, too.
The only thing that still wins out for cheesiness is, as Uber pointed out, the SCM.