Is the Coup level in the Yamato campaign possible?

For those of you who haven't played the level, the idea is that you start off much weaker than the red AI but they'll remain allied with you as long as you tribute them 200 gold whenever they ask for it. That's all well and good in theory, but there doesn't appear to be any gold to mine, so you have to rely on trading with the yellow AI that stays allied with you. But it's impossible to generate enough gold in time -- even if the very first thing you do in the level is build a dock and trading ships, you'll scrape up maybe 10 gold before the AI demands 200 and then immediately attacks you if you don't respond.

The hints suggest fleeing to the yellow island instead, but instead of being an option it appears to be the only viable approach. So is the gimmick in this one completely broken, or am I just missing something?