The Spartans won the Peloponnesian War of 431-404 B.C. by a trick, at least according to Xenophon, the only surviving contemporary historian who covers that period: Lysander captured the Athenian fleet at Aegospotami in 405 B.C. by fooling the Athenians, and that led to the Athenian surrender some months later.
Earlier, in 413 B.C., the Syracusans tricked the Athenians when they were preparing to retreat from their encampment near Syracuse. That helped seal the fate of the Athenian forces, who were almost all killed or captured...but the Syracusans don't seem to have had any misgivings about fooling the Athenians (who had, after all, been trying to capture their city by siege).
If you look at how Homer portrays Odysseus in the Iliad and the Odyssey, he's definitely one of the good guys.
The Greeks had a trickster spirit named DAIMOS, who was not a god but rather a universal malevolent spirit. Any way you slice it, Daimos does not rise to the level of a Set (Egypt) or Loki (Norse).
And yes, Greek did use deception against Greek very often in the wars between the polis, but that does not mean it was a particularly well-thought of tactic.
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.