P.S. Hermes was not a trickster god. He was the God of Commerce and Zeus' messenger.
Very often Greek gods are given more than one power/aspect/portfolio depending on where and how that particular god was worshipped. So, one region of Greece may consider Hermes a trickster, while another does not. The best example of this phenomenon would be Apollo, who was worshipped as a god of the sun, medicine, athletics, and prophecy (probably the most versatile of the gods in this regard).
However, Greek gods regularly come down from Olympus to trick and beguile unsuspecting Greeks. Zeus seduces Leto (amongst others) and begets Heracles, for example. The gods were expected to do no less. Relations between Greeks, however, were supposed to be carried out by different rules.
Greek history is full of examples of even the best generals and politicians being put on trial, and always they are accused of the same things: exceeding their authority, fiscal irresponsibility (or theft), abuse of power, breaking promises, etc. One only has to look at Alcibiades to see this, the greatest traitor and most despised man in Greece. At various times, Thucydides and Pericles (paragons of virtue) are also dragged into "court" and accused of deceptions and lies amongst other things.
Dishonesty and dishonorable actions were even more hated in Ancient Greece than they are today.
"Dishonesty and dishonorable actions were even more hated in Ancient Greece than they are today."
This part of the the discussion started out by saying that the Greeks disdained trickery in warfare. Whatever the validity of that point, trickery in warfare is a completely different thing from dishonesty in every day life. I know of no society that countenances dishonesty in everyday life.