Well, the most popular gyan says that one should have lentils and rice in the ratio of 1:3. I firmly believe in the rule that the kitchen is absolutely rule-free. The proportions, cooking times, ingredients, all change with the kitchen and the mood of the cook. So with the Dosa having become a traveller of sorts, and having reached north from its home in the south, stereotypes surrounding its preparation have been broken.
Let's come back to the original question- "Daal kitni, Chawal kitna?"
Well, I don't mind 1:3, but clearly prefer 1:2. Having more Daal in the batter gives it a character and subdues the fallout of of using north Indian Chawal, whose varaities are as varied as the regions therein. I once used high grade Basmati in the batter with the confidence of a master chef, only to find that the aromatic rice with the enviable taste and the undisputed fame of being the king of rice-varieties was a mega flop. So, the point to take home is the same old gyan of the cookhouse- never go with stereotypes.