I agree that Conclaves should build on essences (more the better, but I don't recall any building in conclaves need more than one essences, I do knew some building need one essences in conclaves) if no essences, then town or fortness would be better off rather than conclaves, but you do want one conclaves at least to reseaching faster if you done all building and not making any troop, but making troop is fortness's job while Town job if all building are done builded, is to do nothing will gain you more gold, while conclaves should speed up reseaching while doing nothing as well...
but as for food, I don't think it's wise to set even it's fortness on 2 grains, how would you level up city? rare I had to get 5 level, but my best one is 3 level even on 4 grains, and that was most on 3 gain food, Yes materials is importian but so was grains too many time I restart game to get a good spot, there is 5 grains meaning might good chance 5 level city, but materials is low like 2 or 1, no way, it's take too long time to build all building to end of game, forget it,
I do want 5 grains 5 material and 3 essences, LOL, but best one I see is 5 grains 4 marterial and 3 essences but for some reason I back out meuns and lost that game, and can't taken back...so I keep restart countless to get something like that, but failed, I spend restart more than playing, restart, restart to get a best or very good land for my first city but map piss me off to no end, they rare gave me a good one, I don't want 3/3/1 or 5/1/0. it's just annying me...