I have though about it a bit more, and I think we should revolt right away. We have 1800 gold in the treasury, that's enough to cashrush 6 markets. Our best moneymakers are Roosting Tree, Donsignia, Camelot and Provolutia. The cities of BlackHole, New London, Warm'ogh and especially Husborne Crawley have good potential (they are a bit small now, but can make a lot of gold with all those rivers - Husborne Crawley has good growth potential). Chaos, Barchester, Rivendell and Skye also have high potential after we move the palace or build a central FP to lower their corruption.
I would suggest to revolt, and (short-)rush markets in Camelot, Roosting Tree and Donsignia right after the switch to republic. Probably also in Husborne Crawley. Provolutia, Oxford and Bentley are also good candidates. Assuming 100% tax, markets in Camelot, RT and donsignia would add some 27 gpt to our income in total, each of the others adds about 5 gpt (with far higher potential returns for HC).
Here's what CivAssist says for our economy under republic (280AD)
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I was thinking of disbanding units after the initial phase of the Indian War, that is, after taking out their western cities. That should shorten our front, or really, for the first time we would have something like a front. I think blocking units will be less needed from then on.
The most obvious candidates for disbanding are the curragh and the warriors.