[Ming]

My reasoning is as follows:

IMHO the key advantage of P3 is to allow you to recruit as many capital-only sacreds as possible as you will very soon find that you'll run out of funds much faster than resources as you expand and build new castles. If one take a lesser production scale, one will end up with less of those awsome capital sacreds but more doom guards (recruited outside of the capital). That is not necessary a poor trade-off if the extra design points can be put to good use - partly because one will run out of supplies very quickly (not to mention pop loss) if one concentrate on the capital only sacreds.