In general, I think we should, when the trading situation changes in the game, do either:
1: Do the trade and explain why we did, which can be followed by a discussion in the team
- OR -
2: If we are not sure what to do, post a save and discuss the trade.
I prefer #2, but I think it is ok to do #1 to have some progression in the game, but "I just did" is not a sufficient explanation in my mind to do #1.
A few (hopefully constructive comments) on the game (plarq's save)
War: First target: Japan. Doesn't seem like they have neither iron nor horses

When they are out of the game we own the island.
Second target: Russia(?). This will give us an exstra lux. Lux = money = research
We could build warriors and later upgrade them swords (? EDIT: We might not have the money for that.).
Empire expansion: We need the lux to the north. One settler and some defends will do it, if we want to settle to the east as well. Here is dotmap:
MM - stuff:
Carthage: Should have +5 food. This is our settler factory and sets the pace for our expansion.
Utica: Why barracks? This is our worker factory. Suggestion: Build settler instead and then workers. Workers should work terrain to make a 2 turn settler factory.
Leptis magna: Won't grow above 6 pops. Build worker at some point.
Theveste: Build barraks. We don't want regular mili.
Leptis minor: Put in barracks. I would have preferred it settled one tile to the north (haven't checked our dotmap)
Ruscade: Build temple to get whales?
We should make a dotmap for the eastern expansion.
Trading: Honestly. I am not sure what to do. Hope that Netherlands get horseback riding and trade it for myst?