Don't forget we want to try and take Valencia in a peace deal after we take most/all of the northern cities and leave KK goth. We could take out HC during the peace treaty and save Goth as the last city on the map that's not ours. The culture from valencia may get the clams so we don't have to raze Madrid. But probably not as it will take a few turns even with culture+running artists to get the 2nd border pop.
With time frame left that is a big ask. 3 turns to war? 8-9 turns war? 10 turns peace? Sounds risky now? Might be easier to buy a galley and take city the old fashioned way.