stealth_nsk
Deity
I'm confused. Why would you ever run anything except Ilkum and/or Colonization (+30 % production towards Builders and +50 % towards Settlers, respectively) in the early game? Why would I want +1 production in all cities, when these whopping bonuses dwarf that paltry amount in the things that really matter and which you would be doing anyways (occupying new land or developing existing holdings)?
Let's you build settlers half of the time. This means the Colonization gives only 25% bonus, so with less than 4 production per city it will give less than Urban Planning. The more time you spend on other things - the less effective Ilkum/Colonization is.
Optima strategy would be to switch those policies on during the time of actively building Settlers/Builders and switch off while building other things, but this would require a lot of planning and sync between different things going on.