[PvK]

My typical antidote to giants is superior numbers of cannon fodder and missile troops, perhaps combined with spells but no valuable well-armored troops. Both Arcos have Cardaces, which are good cheap light/medium infantry with a very low resource cost - I would expect them (supported by indy archers, for example) to do very well against Jotun giants in a war of attrition. I would leave the myrmidons at home but might use some Icarids to try to take out the Jotun mages.

That is, I think GE also has more efficient infantry, if the player doesn't waste myrmidons or Wind Riders against things that make their armor irrelevant, like giants. Use the Cardaces and/or Peltasts or other light infantry and archers (and/or mages) against giants.

Note that Arco not only has 50-gold/5-research philosophers, but their labs only cost 100 gold. When they are building Myrmidons, they tend to have gold to spare, so it's well worth it to build several labs and have them all cranking out cheap researchers.

PvK