Air door carbs are forgiving. The carbs with more vacuum pods can cover different driving conditions. The variablity in the transitional circuit is important too. Some holleys have like 3 holes. That is fine, for the app it is all you need. Holley is all open jets. A springed rod and jet system can offer some driveability improvement. Untill it causes a lean in the carb circuit.
The Qjet on my old car 3.8 231 v6 was 750cfm . Not sure if the secondaries ever opened up much. The secondary pod also wont unlock them until the condition is right. It did not bog at wot. 750cfm on a stock 1976 231, is overcarburetion in my book.