If all that happened was Bowie stayed low and didn't do anything to draw attention to himself, then all might have been well. He spent a few weeks in Terran without incident after all.
But let's review what happened in Barca. First, there was a new realm formed close to the Zuma. That would definitely draw some attention. Not a lot, but more than usual, which is to say, none. So for at least a few days, one would think Barca would be watched to see how the nearest realm to the south might develop. And here's where the mistake came. In this new realm, the closest to the Zuma's south, you made Bowie the duke of its one and only region. That, you see, was a mistake.
In the end, I think things turned out alright. The original "escape clause" was to have you execute Bowie yourself. Had Bowie not challenged the Zuma, thus opening another method of potentially killing him, Barca would most likely have been wiped. So lesson learned I guess is, the Zuma aren't nice friendly drinking buddies and their lands aren't places to take your family on picnics. They are scary, they are fierce, and they have very long memories.
