I always thought that 砲 is trebuchet or catapult because Chinese chess predates the gunpowder age.
If 相象 is elephant, would there not be two mounted warrior class? Since the equivalent in English is Bishop, I thought the Chinese equivalent is like a premier (like Wen Jia Bao) because
仕士 is like scholars/elders. It makes sense because the scholars and minister usually stay in the tent to give advise. Whereas 相象 or premier like Zhuge Liang will go out in battle occasionally (but not in front line).
Since then, 帥將 is more like commander-in-chief. He is the one pulling string in the tent.
In Chinese military system, the scholars always has a hand in battle. There is more of a "management" issue involved. The chinese chess board is more like a war wheras chess is only liken to a battle.